Savestate

From Glitch City Wiki

A savestate (also known as a snapshot) is a file that when loaded on most emulators updates save data to an exact point, without having to do anything other than load the file. Savestates even save the point where the background music is. Often they are easier to use than a save file, as no saving operation has to be done within the game. The common file extension for savestates is .sn*, * being a one-digit number. As the filename of savestates must correspond exactly with that of the ROM it is for, the number in the extension is used for multiple savestates to exist for one ROM. Savestates are created by dumping the game's RAM data into a readable file used by the emulator.