Tool Assisted Speedruns (occasionally Tool Assisted Superplays) or TASes are a subset of speedruns that are created in an emulator with the aid of tools. The goal of a TAS it to play through the game as fast and precisely as possible. The use of tools allows for many strategies and routes not normally possible by a human runner.
TASes are not created to compete with standard speedruns and often times speedruns and TASes share information to help each other improve.