A special file used in many **Version Control** Systems which specifies files to be excluded from **version control**. In Unity projects, several files can be excluded from **version control**. Using an Ignore File is the best way to achieve this. See [Using external version control systems with Unity](https://docs.unity3d.com/Manual/ExternalVersionControlSystemSupport.html).
#### Project
In Unity, you use a project to design and develop a game. A project stores all of the files related to a game, such as the asset and **Scene** files. See [2D or 3D projects](https://docs.unity3d.com/Manual/2Dor3D.html).
A system for managing file changes. You can use Unity in conjunction with most **version control** tools, including **Perforce** , Git, Mercurial, and perforce. See [Version Control](https://docs.unity3d.com/Manual/VersionControl.html).