Glossary of Key Terms
Non-spatial information associated with geographic features. This data describes the characteristics of the features (e.g. name, population, land use type). An attribute table has rows and columns of non-spatial, contextual information.
A background layer that provides geographic context for the other data layers displayed on a map. Base maps typically offer fundamental geographic information such as roads, water bodies, administrative boundaries, and sometimes terrain or satellite imagery. They serve as a reference framework upon which other data layers (e.g. the locations of schools or environmental data) can be overlaid and analyzed.
The control panel is the element of the user interface that provides access to various functions, settings, and tools for managing and manipulating the map or the software itself. It often contains buttons, menus, toolbars, and dialog boxes.
Information about the location, attributes, and properties of geographic features. It essentially represents the real world in a digital format, linking locations on the Earth’s surface with descriptive information.
A single geographic entity, such as a street or a building, with both a spatial location (latitude and longitude) and attributes (data about it).
Geographic Information System, the technology and data that represent, analyze, and visualize geographical information. ArcGIS is a suite of GIS applications designed and licensed by the company Esri. ArcGIS Online is their cloud-based platform for sharing maps and data.
A single collection of data or features displayed on a map, like roads, buildings, air quality values, county lines, etc. May also be called a “data layer” or a “map layer.”
A visual key that explains the symbols, colors, patterns, and other visual elements used to represent features and their attributes on a map. The legend helps map readers understand what the different graphical elements on the map signify. For each unique symbol or color used, the legend provides a corresponding description.
The geographic area displayed on a map—i.e. the visible map window. Essentially, it’s the “frame” or “viewport” through which you are viewing the spatial data. Adjusting the map extent allows you to zoom in to see a smaller area in more detail or zoom out to see a larger area at greater scale.
Information describing the data itself, like its source, format, and quality.
A scale used to report air quality associated with the six Criteria Air Pollutants regulated by their concentration according to the National Ambient Air Quality Standards (NAAQS). NAAQS are determined via health and air quality research, and the regulation process is within the framework of the federal Clean Air Act and its Amendments. AQI tells you how clean or polluted your air is, and which associated health effects might be a concern for you. AQI values ranges from 0 to 500, with higher values indicating greater levels of pollution and greater immediate public health risk.
A colorless, odorless, and poisonous gas formed by the incomplete burning of carbon-containing fuels. It reduces the ability of blood to carry oxygen, with potentially serious health consequences leading to death.
The six Criteria Air Pollutants are carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter (PM2.5 and PM10), and airborne lead (Pb). These are the air pollutants for which the U.S. Environmental Protection Agency (EPA) has established National Ambient Air Quality Standards (NAAQS) to protect public health and welfare within the framework of the federal Clean Air Act and its Amendments. Criteria Air Pollutants are regulated according to their concentration in the air, while Hazardous Air Pollutants are regulated according to their emission levels into the air.
The release of pollutants into the air from a source.
Air pollutants known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects. The EPA regulates numerous HAPs. Examples include benzene, mercury, and asbestos. Hazardous Air Pollutants are regulated according to their emission into the air, while Criteria Air Pollutants are regulated according to their concentration in the air.
A toxic metal historically used in gasoline, paint, and industrial processes. Exposure can cause neurological and developmental problems.
An invisible gas composed of three oxygen atoms. Ground-level ozone in high concentration is a harmful air pollutant created by chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight and heat. Stratospheric ozone, higher in the atmosphere, protects us from harmful UV radiation.
A gas formed when fuel is burned at high temperatures, such as in vehicle engines and power plants. It contributes to the formation of ozone and acid rain. In high concentration, nitrogen dioxide can cause the atmosphere to appear reddish-brown.
Tiny solid or liquid particles suspended in the air. PM in higher concentration dramatically reduces visibility, and in lower concentration can cause a visible haze. PM is further classified as PM10 or PM2.5. PM10 particles have diameters 10 micrometers or smaller, and includes dust and the smallest pollen grains. PM2.5 particles have diameters 2.5 micrometers or smaller. PM2.5 is more harmful than PM10 as it can penetrate deeper into the lungs.
Any place or activity that releases pollutants into the air. Sources can be stationary (e.g., factories, power plants) or mobile (e.g., cars, trucks, airplanes).
A regulatory monitor refers to an air quality monitoring station or device that is specifically established and operated to measure concentrations of Criteria Air Pollutants for evaluation against the National Ambient Air Quality Standards (NAAQS). These measurements are used in the regulatory and enforcement process mandated by the federal Clean Air Act and its Amendments. Regulatory monitors are overseen by the federal EPA, but data management and maintenance is often delegated to state, local, or tribal air or environmental agencies who report back to the EPA. Since the data they gather can be used for enforcement, regulatory monitors follow a strict protocol for maintenance and data quality.
A colorless gas with a pungent odor, primarily released from the burning of fossil fuels containing sulfur (especially in power plants and industrial processes). It contributes to acid rain and respiratory problems.
Organic chemical compounds that evaporate easily at room temperature. VOCs are emitted from a variety of sources, including paints, solvents, gasoline, and industrial processes, and contribute to the formation of ground-level ozone. Many VOCs are also listed as Air Toxics. Many, but not all, VOCs are detectable by humans via their odor.
The “current” reading reflects the data at the time the user opened or last refreshed the map. Users can manually update the current readings by clicking the refresh button on the Map Control panel.
The PurpleAir sensor data on the AirKeeper Dashboard dates back to December 12, 2016 for the oldest sensors that were already installed at that time. All other sensors will only have data starting from their installation date.
Select “Apply” to see your selections on the map.
This selection summarizes sensor data at the county level. It is the default view when opening or refreshing the AirKeeper Dashboard. The shaded color of each county represents the average AQI for the sensors located in that county. The Result Type can be changed to view county summaries as average PM2.5 concentrations or sensor counts.
This view displays individual sensors as shaded circles on the map, dependent on their U.S. EPA PM2.5 AQI reading. The default view for individual sensors displays only sensors located in the state of North Carolina. To view sensors that might be outside North Carolina in a bordering state, select the radio button for “Include 20 km buffer.” Doing so will display any sensors within 20 kilometers of the North Carolina state border.
This view summarizes sensor data at the zip code level. The shaded color of each zip code is based on the average AQI for the sensors located in that zip code. The Result Type can be changed to view zip code summaries as average PM 2.5 concentrations or sensor counts.
Correction factors are used in air quality analysis to account for factors that may influence the sensor readings in an undesirable way. Examples of factors that may influence sensor readings include but are not limited to electrical noise, temperature, humidity, and barometric pressure. A range of correction factors exist, such as those used to assess exposure to wood smoke in indoor environments, or those that account for ambient humidity in PM2.5 particles sensors. Checking this box applies the EPA recommended correction factor to the data, which utilizes the relative humidity reported by the PurpleAir sensors and accounts for some of the bias that may exist. Ultimately, correction factors can be seen as a tool to improve the accuracy of air pollution exposure measurements. The correction factor applied to data in the AirKeeper Dashboard is the ALT CF=3.4 data from PurpleAir, which is described in detail by this PurpleAir Community Post: https://community.purpleair.com/t/what-is-the-difference-between-cf-1-atm-and-alt/6442/1.
Provides options for users to select from which will serve as the period over which the PurpleAir sensor’s US EPA PM2.5 AQI or Concentration ug/m3 values will be averaged. “Real-time” will display the latest data value, pulled approximately every 45 minutes to one hour. The “1-Hour” selection displays the average sensor reading starting at the top of the hour. The “1-day” selection displays 24-hour average data for the sensor starting at midnight. The 1-hour and 1-day selections do not pull in new data, but rather group the real-time data by the specified period.
Air quality concentration is measured in micrograms per cubic meter and reflects the amount of air pollutant material per unit volume of air. Thus, selecting “concentration µg/m3” from the dropdown shows the micrograms of fine particulate matter (PM2.5) per cubic meter of air. Air quality concentrations are used to calculate the Air Quality Index (AQI), which is a scale used to represent air quality’s relationship to public health.
Defaulted to average, the metric dropdown allows users to select either “average” or “maximum” from the dropdown. Selecting “average” will display the average data for the selected period of time, whereas “maximum” will display the maximum value.
The mass of particles with diameters less than 2.5 micrometers (30x smaller than a grain of table salt) per unit volume of air is known as the “PM2.5 mass concentration” and is usually reported in physical units of micrograms (millionths of a gram) per cubic meter. The “PM” stands for “Particulate Matter.” The PM2.5 mass concentration is used to determine the PM2.5 Air Quality Index (AQI) via ranges described by the EPA and linked to the NAAQS. AQI is used to communicate the level of health concern in six color-coded categories. Selecting this result type from the dropdown displays the EPA’s Air Quality Index categorization on the following scale:
When “U.S. EPA PM2.5 AQI” is selected as the Result Type, the shading on the map indicates the AQI reading at the sensor.
Note that in February 2024, the U.S. EPA lowered the federal annual standard for PM2.5 from 12.0 micrograms per cubic meter (µg/m3) to 9.0 µg/m3, and updated the PM2.5 AQI breakpoints to capture this change.
The mass of particles with diameters less than 2.5 micrometers (30x smaller than a grain of table salt) per unit volume of air is known as the “PM2.5 mass concentration” and is usually reported in physical units of micrograms (millionths of a gram) per cubic meter. The “PM” stands for “Particulate Matter.” The PM2.5 mass concentration is used to determine the PM2.5 Air Quality Index (AQI) via ranges described by the EPA and linked to the NAAQS. AQI is used to communicate the level of health concern in six color-coded categories. Selecting this result type from the dropdown displays the EPA’s Air Quality Index categorization on the following scale:
When “U.S. EPA PM 2.5AQI” is selected as the Result Type, the shading on the map indicates the AQI reading at the sensor.
Note that in February 2024, the U.S. EPA lowered the federal annual standard for PM2.5 from 12.0 micrograms per cubic meter (µg/m3) to 9.0 µg/m3, and updated the PM2.5 AQI breakpoints to capture this change.
Filter for PurpleAir sensors that are active, meaning they are visible as a color on the map because they are online and pulling in readings.
Filter for PurpleAir sensors in the CleanAIRE NC Network.
Filter for PurpleAir sensors that are inactive, meaning they have gone offline, or all channels have become downgraded. Sensors are marked as inactive in the Dashboard if they have no data within one day of the end of the selected period.
Filter for PurpleAir sensors located inside a home, office, school, or other building.
Users can select a sensor by clicking one on the map, and toggling “Select Sensor” in the sensor pop-up. This can also be achieved by selecting the same toggle for a sensor in the “Sensor Table and Download” pop-up at the bottom of the map. Once one or more sensors have been selected, users can use this filter to only show those sensors that have been selected.
Filter for PurpleAir sensors located outside in a backyard, local park, street, or other outdoor environment.
The 11-digit number that uniquely identifies the census tract in which the sensor is located.
The name of the county in North Carolina (or a bordering state) in which the sensor is located.
The latitude and longitude coordinates that uniquely describe the location of the sensor.
Depending on the user-selected averaging period and metric values, this will display either the most recent observation (real-time), the hourly average/maximum since the top of the hour (1-hour), or the daily average/maximum since midnight (1-day).
This toggle allows the user to select one or multiple sensors. Once one or more sensors have been selected, the “only show my selected sensors” checkbox in the “Filter by Sensor Type” of the panel allows users to view only their selected sensors on the map.
The state in which the sensor is located.
Radio buttons above the time series chart allow users to view US EPA PM2.5 or PM2.5 Concentration values. The legend below the time series chart delineates daily average, hourly average, and the real-time measurements. Options to zoom, download as an image, or download as a CSV file are available to the top right of the time series chart.
The zip code in which the sensor is located.
This data layer locates sites within North Carolina that are regulated under the Clean Air Act (CAA). North Carolina’s Division of Air Quality is authorized by the EPA to administer the air quality program in North Carolina and classifies air quality permits as Title V (Major), Synthetic Minor, Small (Minor), Permit Exempt, or Registered. Facilities in North Carolina’s Buncombe, Forsyth, and Mecklenburg counties are not included in this dataset as they have their own local air programs that enforce federal, state, and local air regulations.
This data layer displays the locations of nursing homes in the state of North Carolina. Nursing homes are a place of residence for people who require constant nursing care and have significant deficiencies with the activities of daily living. This layer includes currently active nursing homes and provides additional information such as the number of certified beds, the address, and the average number of residents per day.
This data layer comes from the “PLACES: Local Data for Better Health” dataset, a collaboration between the Centers for Disease Control and Prevention, the Robert Wood Johnson Foundation, and the CDC Foundation. Age-adjusted asthma prevalence is shown for people over the age of 18, at the county level, for the state of North Carolina.
This data layer comes from the “PLACES: Local Data for Better Health” dataset, a collaboration between the Centers for Disease Control and Prevention, the Robert Wood Johnson Foundation, and the CDC Foundation. Age-adjusted cancer prevalence is shown for people over the age of 18, at the county level, for the state of North Carolina.
Created by the North Carolina Department of Transportation’s Archaeology Group, this data layer displays the locations of thousands of cemeteries in North Carolina. Topographic maps from the U.S. Geological Survey were used to identify the sites as well as those identified during archaeological survey work, and when possible, the cemeteries were verified through aerial imagery, street view, and parcel data. Annual maintenance of this dataset is handled by the NCDOT Archaeology Group.
This data layer is managed by the Geospatial Management Office under the U.S. Department of Homeland Security. The Homeland Infrastructure Foundation-Level Data (HIFLD) provides access to data on critical infrastructure, in this case the locations of child day care centers for all 50 U.S. states, Washington D.C., and Puerto Rico. This data accounts for center-based child day care locations (including those located at schools or religious institutes) and does not include group, home, or family-based child day cares.
This data layer comes from the “PLACES: Local Data for Better Health” dataset, a collaboration between the Centers for Disease Control and Prevention, the Robert Wood Johnson Foundation, and the CDC Foundation. Age-adjusted chronic obstructive pulmonary disease (COPD) prevalence is shown for people over the age of 18, at the county level, for the state of North Carolina.
This data layer is managed by the Geospatial Management Office under the U.S. Department of Homeland Security. The Homeland Infrastructure Foundation-Level Data (HIFLD) provides access to data on critical infrastructure, in this case college and university campuses. The population for the college or university must exceed 500. Included are doctoral/research universities, masters colleges and universities, baccalaureate colleges, associated colleges, theological seminaries, medical schools and other health care professional schools, schools of engineering and technology, business and management, art, music, design, law schools, teachers’ colleges, tribal colleges, and other specialized institutions. Excluded are online institutions and administrative records as well as colleges and universities that do not have a verifiable campus map.
Through the County Health Rankings, a program of the University of Wisconsin Population Health Institute with support from the Robert Wood Johnson Foundation, health metrics were measured across nearly all counties in the nation and ranked within states. This data layer represents the 2023 County Health Rankings in North Carolina, which are derived from county-level measures from various national and state data sources. Some example measures included are rates of adult smoking, physical inactivity, and flu vaccinations.
The National Oceanic and Atmospheric Administration (NOAA) maintains this data layer hourly from their METAR and buoy data. A typical Meteorological Aerodrome Report (METAR) contains multiple weather variables for each land-based location, as do the moored weather buoys from the National Data Buoy Center.
This Esri-owned layer displays lands in the United States that are managed by the U.S. Department of Defense. A filter has been used on the USA Federal Lands layer to provide this view of the over 30 million acres of land managed by the U.S. Defense Department.
This layer shows how neighborhoods in urban spaces were divided and graded by the U.S. government’s Home Owners Loan Corporation (HOLC) in the late 1930s. The HOLC created maps for more than 200 American cities and assigned grades to neighborhoods to document the mortgage security on a neighborhood- by-neighborhood basis. HOLC assigned mortgage security grades so that money lenders could then use the information to refuse loans. The grades were color-coded such that green areas were considered first grade or best, blue areas were second grade (but still desirable), yellow areas were third grade or definitely declining, and red areas were fourth grade or hazardous. HOLC also documented other information about the neighborhood to justify their grades, and one key element was the race and ethnicity of residents. Neighborhoods with high proportions of African American and immigrant residents were systematically rated as yellow or red by the U.S. HOLC. Thus, redlining was an explicitly racist policy that intentionally forced segregation and massively benefitted white populations over all others. One legacy of redlining is that air pollution permits are often more concentrated in formerly redlined neighborhoods. Similar but less documented discriminatory practices have taken place in towns and rural areas across North Carolina and beyond. This layer represents only a small number of well-researched areas with available historic redlined maps.
This data layer comes from the “PLACES: Local Data for Better Health” dataset, a collaboration between the Centers for Disease Control and Prevention, the Robert Wood Johnson Foundation, and the CDC Foundation. Age-adjusted heart disease mortality rates are shown for people over the age of 35, at the county level, for the state of North Carolina.
The North Carolina Department of Transportation’s ESRI Roads and Highways system generates the data for this layer, which is comprised of all State Maintained Roads. The primary routes included are interstates, U.S. routes, and North Carolina routes.
This feature layer, utilizing National Geospatial Data Asset (NGDA) data from the U.S. Geological Survey, displays hospitals, medical centers, ambulance services, fire stations, and EMS stations in the U.S.
This data layer assesses and identifies communities that have been disadvantaged according to the Justice40 Initiative criteria. Census tracts are shaded in different hues of blue to denote the disadvantaged communities. A community is considered disadvantaged on the map if it is in a census tract that is 1) at or above the threshold for one or more environmental, climate, or other burdens; and 2) at or above the threshold for an associated socioeconomic burden. Additionally, a census tract that is completely surrounded by disadvantaged communities and is at or above the 50% threshold for low income is also considered disadvantaged.
This data layer covers facilities with air permits in Mecklenburg County, one of the three counties in North Carolina that does not report its air permits to the North Carolina Division of Air Quality. The air permits in Mecklenburg County display as gray dots on the map; selecting one will open a pop-up window complete with information such as the site name, address, coordinates, classification code, whether the facility is active, and more.
This data layer comes from the “PLACES: Local Data for Better Health” dataset, a collaboration between the Centers for Disease Control and Prevention, the Robert Wood Johnson Foundation, and the CDC Foundation. Age-adjusted mental distress prevalence is shown for people over the age of 18, at the county level, for the state of North Carolina.
The Federal Emergency Management System (FEMA) and the state of North Carolina partnered to modernize flood maps under the NC Floodplain Mapping Program (NCFMP). The data in this layer represents areas within the flood mapping boundaries defined by the engineering models for the 100-year, 500-year, and floodway. These zones are used by FEMA to identify areas of coastal high-hazard flooding and for insurance rating purposes.
This data layer displays a thick purple border around the congressional districts from which members of the US House of Representatives are elected and subsequently represent North Carolina in the United States Congress. One representative is elected from each of the 14 districts, and terms are two years in length. The layer is maintained by the NC Legislature.
This data layer displays a thin purple border and number associated with each North Carolina State House District from which members of the NC House of Representatives are elected from and subsequently represent.One representative is elected from each of the 120 districts, and terms are two years in length. The layer is maintained by the NC Legislature.
This data layer represents Animal Feeding Operation permits managed by the Division of Water Resources within North Carolina’s Department of Environmental Quality. Animal operations are defined as feedlots involving more than 250 swine, 100 confined cattle, 75 horses, 1000 sheep or 30,000 poultry with a liquid waste management system by General Statute 143-215. 10B. Please note that dry waste operations are excluded from this data, meaning that most poultry operations are not captured by this layer.
This data layer reflects all permitted (whether active or closed) Municipal Solid Waste (MSW), Construction and Demolition (CDLF), Land Clearing and Inert Debris (LCID), and Demolition (DEMO) landfill facilities in the state of North Carolina. Maintained by the North Carolina Department of Environmental Quality under the Division of Waste Management, the purpose of this data layer is to create a visual overview of facilities that undergo inspections and groundwater monitoring as part of facility management.
This data layer displays the names and locations (address) of places of worship in North Carolina. The data comes from an “All Places of Worship” dataset from the IRS master files which was then queried to include only places of worship that are 501(c)(3) non-profit organizations. This dataset was then delivered to the Homeland Infrastructure Foundation-Level Data (HIFLD) where the HIFLD Support Team performed additional quality control tasks on the dataset.
This data layer is managed by the Geospatial Management Office under the U.S. Department of Homeland Security. The Homeland Infrastructure Foundation-Level Data (HIFLD) provides access to data on critical infrastructure, in this case public elementary and secondary education facilities in the United States as defined by the Common Core of Data, National Center for Education Statistics, and U.S. Department of Education for the 2022 – 2023 school year. This includes all kindergarten through 12th grade schools as tracked by the Common Core of Data.
Selecting this air quality layer displays PurpleAir sensors reporting the U.S. EPA PM2.5 AQI, which refers to Air Quality Index (AQI) values calculated on the concentration of fine particulate matter (PM2.5) in the air. This indicates how polluted the air is with these harmful chemicals. Note that a higher PM2.5 AQI value means a higher level of particulate matter present in the air, posing a greater health concern. See Apply Correction Factor for information about management and display of PurpleAir data in the AirKeeper Dashboard.
This data comes from the North Carolina Department of Transportation’s Rail Division and includes line features representing all standard gauge freight and passenger railroad tracks in North Carolina.
Regulatory monitors are ambient monitoring systems operated by federal, state, local, and tribal air agencies. Data from Regulatory Air Monitors covers measurements for pollutants such as ozone (O3), PM2.5, PM10, carbon monoxide (CO), nitrogen dioxide (NO2), and sulfur dioxide (SO2). See Air Quality Terms for more info.
This data displays projected visible surface smoke across the contiguous United States for the next 48 hours in 1-hour increments; it is updated every 24 hours by the National Weather Service. The data comes from the National Digital Guidance Database (NDGD).
This data layer comes from the “PLACES: Local Data for Better Health” dataset, a collaboration between the Centers for Disease Control and Prevention, the Robert Wood Johnson Foundation, and the CDC Foundation. Age-adjusted smoking prevalence is shown for people over the age of 18, at the county level, for the state of North Carolina.
The North Carolina Department of Transportation maintains this data layer, which contains point and line representations of projects under the 2023 – 2024 Statewide Transportation Improvement Program (STIP). Transportation projects are further subdivided by category: interstate; rural; urban; bridge; municipal bridge; bicycle and pedestrian; congestion mitigation; highway safety improvement program; ferry; passenger rail; and roadside environmental.
The National Digital Forecast Database (NDFD) provides the data for this layer, which displays the maximum air temperature forecast over the next three days across the contiguous U.S., Alaska, Guam, Hawaii, and Puerto Rico in daily increments. While the minimum temperatures are typically at night and the maximum temperatures are typically in the afternoon, all temperatures are forecast in degrees Fahrenheit. NDFD contains digital forecasts from the National Weather Service in collaboration with the National Centers for Environmental Prediction (NCEP) under the administration of NOAA.
This data layer presents urban versus rural populations at the county level; zooming in will display this information at the census tract level as well. Selecting a county or census tract in North Carolina will open a pop-up window that displays the urban or rural status of the population as well as the total population, total housing units, population by race and ethnicity, as well as an age breakdown, for that county or census tract. This data is pulled from the U.S. Census Bureau’s 2020 Census Demographics and Housing Characteristics data, which includes information about total population counts by sex, age, and race for the nation, state, county, census tract, and block groups in the U.S. and Puerto Rico.
This data layer displays national and state parks and forests, as well as county, regional, and local parks within the United States. The data layer is owned by Esri.
Location and facility information for wastewater treatment plants are provided through this layer, from the Integrated Compliance Information System (ICIS). ICIS contains a subset of the Permit Compliance System (PCS) which supports the National Pollutant Discharge Elimination System (NPDES) and contains all federal administrative and judicial enforcement actions. This layer displays publicly-owned treatment works (POTW) and federal facilities; major, minor, and other/non-classified facilities; as well as facilities with combined sewer outfalls.
A comma separated values (CSV) file is a plain text file that stores data in a tabular format. Each line represents a record and values within each line are separated by commas.
A GeoJSON file is a format for encoding geographical data structures using JavaScript Object Notation (JSON). GeoJSON files are commonly used to represent geographic features, such as points, lines, and polygons with their associated attributes.
A GPS Exchange (GPX) format file is a standard way to store and exchange GPS data such as routes and tracks between different applications and devices. GPX files allow users to share, save, and transfer geographical information like points of interest, paths, and recorded paths.
Also known as KMZ. The KML is Google’s standard file format for spatial data. KML stands for Keyhole Markup Language. KMZ is the zipped (compressed) version of KML. KML/Zs are handy for web-GIS and can be used in Google Earth, Google Maps, and Google Fusion Tables. You can convert KML/Z to shapefile as well.
A common file format in Geographic Information Systems (GIS), shapefiles store geospatial data—location, shape, and attributes of geographic features.
A GIS URL (Uniform Resource Locator) is a web address specifically designed to access and interact with geographic information, services, and applications online.
