ESRI Grid is a raster data storage format used by Esri's ArcGIS software for representing geographic data. It's a proprietary format designed for storing and managing raster datasets, which are essentially images composed of cells or pixels, each representing a specific value. These values can represent various geographic phenomena, such as elevation, temperature, land cover, or population density. ESRI Grids are commonly used in geographic information systems (GIS) for spatial analysis, modeling, and visualization. The format supports both integer and floating-point data types, allowing for the representation of discrete and continuous data. ESRI Grids are typically stored as a directory containing multiple files, including a header file that describes the grid's properties, such as cell size, spatial extent, and data type, and data files that contain the actual cell values. Because it is a directory-based format, it is important to keep all the files together for the grid to be properly read and interpreted by GIS software. The format is optimized for efficient storage and retrieval of raster data, making it suitable for large datasets.