The various uses of OAuth are as follows:
- As discussed, it can be used for authentication. You might have seen it in various applications, displaying messages such as sign in using Facebook or sign in using Twitter.
- Applications can use it to read data from other applications, such as by integrating a Facebook widget into the application, or having a Twitter feed on your blog.
- Or, the opposite of the previous point can be true: you enable other applications to access the end user's data.