The client is the program that a player uses to connect to an MMORPG's server in order to play the game. It is possible to create a 'browser-based' MMORPG, where the client is the player's web browser, but both Final Fantasy XI and Final Fantasy XIV have taken the more usual route of writing single-purpose, proprietary software clients. The client is what is on the player's game disc. Most of the game's data and program never leaves the server, meaning that without a server to play on, the client program is worthless. Any game data that is handled by the client is subject to hacking by third party tools; in both Final Fantasy XI and Final Fantasy XIV, this includes the player's current location.