ZST is an extension used in files to save the state of video games that are run with the ZNES emulator. It is a tool that allows you to run programs originally created for the Ninetendo console on computers with Windows or Linux systems. ZST files store information about your progress in the game, so you don't have to start the game from scratch every time. Some games allow you to save a few progress points in the game.

Super Nintendo Entertainment System (SNES) is a console that premiered in 1990 as a device with a 16-bit architecture.