An update or patch is a software package the game developer releases through console-specific network channels. An update implements a series of game patches, running software code that fixes abnormal game execution and known software bugs.

Whenever an update has been released for a specific type of console, it will be automatically dispatched for download to any PC, PlayStation or Xbox console while connected to their respective online service: Steam, PlayStation Network / PSN or Xbox Live.

It is mandatory for a player to accept any released software update in order to be able to play the game online. It is possible to decline an update. However, on doing so, the player will be disconnected from the online service.

For Modern Warfare 2, see Call of Duty: Modern Warfare 2 Updates.
For Black Ops, see Call of Duty: Black Ops Updates.
For Black Ops II, see Call of Duty: Black Ops II Updates.