A shapefile is a popular geospatial vector data format for geographic information systems (GIS) software. It is developed and regulated by Esri as a mostly open specification for data interoperability. A shapefile spatially describes geometry as points, lines, and polygons, representing geographic features like roads, rivers, and land parcels. It is important to note that a 'shapefile' actually comprises multiple files, typically at least three: .shp (the main file containing the feature geometry), .shx (an index file that speeds up spatial queries), and .dbf (a dBase table storing attribute data associated with each feature). Other optional files, such as .prj (projection information), .sbn and .sbx (spatial index), and .xml (metadata), can also be part of the shapefile set. Shapefiles are widely used for storing and exchanging geospatial data due to their simplicity and compatibility with various GIS applications. However, they have limitations, such as a 2GB size limit and lack of support for storing topology within the file structure.