The Xbox Memory Card is a memory unit used with the Xbox. It was produced from 2000 to 2008.
The memory card was an alternate way to save game states. Players could copy a save from a game on their system to the card, then take the controller with the memory card in it to another system to play their saves on that console. To use a memory card, the user must connect the card into either of the two memory card ports on their controller while also having said controller plugged into the console for the data to be readable by the console.