Here's the breakdown:
* Action Replay devices are cheat devices. They allow you to modify game data, giving you advantages like unlimited lives, infinite ammo, and more.
* The Action Replay itself doesn't contain games. It acts as a tool to enhance the games you already own.
* To play a game, you need the game cartridge or disc. The Action Replay simply allows you to modify the game's data while it's running.
So, to answer your question directly: You need to have the actual game cartridge or disc inserted into your console for the Action Replay to work.
Here's an analogy: Think of the Action Replay as a magic wand that lets you change the rules of a game. You still need the actual game board and pieces to play.