The OSM file format is a data format used by OpenStreetMap (OSM), a collaborative project to create a free editable map of the world. OSM files store geographic data, including points of interest (POIs), roads, buildings, and other features, represented as nodes, ways, and relations. Nodes are points with latitude and longitude coordinates. Ways are ordered lists of nodes representing linear features like roads or rivers. Relations are used to group nodes, ways, and other relations to represent more complex features like bus routes or administrative boundaries. The OSM format is typically XML-based, although other formats like Protocolbuffer Binary Format (PBF) are also used for efficiency. OSM data is used in a wide range of applications, including navigation systems, mapping software, and geographic information systems (GIS). The open and collaborative nature of OpenStreetMap makes it a valuable resource for creating and maintaining up-to-date and detailed maps.