This document provides an overview of OpenStreetMap (OSM), including its history and components. OSM is a collaborative project to create a free editable map of the world. It was founded in 2004 in response to most geographic data being closed or limited at the time. The project has grown significantly since, with over 500,000 registered contributors as of 2011. Quality is ensured through peer review and tools that help identify issues. Contributors are motivated by factors like having fun exploring new areas, helping with humanitarian causes through groups like HOT, and the increasing use of OSM in commercial and professional applications.