The document describes how a taxi booking app works. It includes sections on the driver sign up process, how customers can make booking requests and view available cabs, how fares are calculated, descriptions of the passenger app, driver app and admin panel modules, and the technologies used including Android, iOS, PHP and a MySQL database. The overall workflow begins with drivers signing up, then customers requesting bookings by selecting pick up and drop off locations, and fares being calculated based on distance and time.