Apps are tools that extend 's functionality. Apps can do things on like open issues, comment on pull requests, and manage projects. They can also do things outside of based on events that happen on . For example, a App can post on Slack when an issue is opened on .
For more information about using Apps, see About using Apps.
For more information about building Apps, see About creating Apps.
also supports OAuth apps. In general, Apps are preferred over OAuth apps. Apps use fine-grained permissions, give the user more control over which repositories the app can access, and use short-lived tokens. These properties can harden the security of the app by limiting the damage that could be done if the app's credentials were . For more information, see Differences between Apps and OAuth apps.