The Quick Start Guide provides instructions on how to set up the most common application link configuration.
If you want to set up application links with a different configuration, see the Administering Application Links.
The administrator's guide is for administrators who want to configure application links for the applications. The guide contains information on adding a new application link, configuring the authentication for an application link, setting up entity links and more.
These resources are for developers who want to develop with the Application Links plugin. Take a look at the Development Hub.