Ultimately, Fusion Server is the back end for your search applications.
Fusion App Studio is a tool for developing a search interface from within the Fusion workspace, using a simple configuration wizard and an integrated code editor. You can set up a simple search interface in just minutes, and then customize it to suit your organization.
If you develop your own search application from scratch, it must make calls to Fusion’s REST API in order to retrieve search results or perform other actions, such as uploading blobs, modifying user roles, or sending messages.
Certain features require configuration on the Fusion back end before you can surface them in your application. The Search Development Guide explains these in detail: