The nexxOMNIA API was designed to offer every Functionality, that is needed for a complete Media Management System in one single, consistent System. It serves many Purposes, but you can seperate it into three different Segments.
Most important is the Media API. You can use it to query for Media Items of every Streamtype. Therefore, its mostly related to Frontend Jobs - i.e., to get the necessary Data to show the Media Items on a Frontend.
For Backend Processing, the Management API is used. Its designed to allow the accesing Users to create, modify and delete Media Items programmatically without the need for a UI. It also allows Access to statistical Data and Analytics.
Furthermore, the Concept of a "Notification Gateway", i.e., a Pinging Mechanism of nexxOMNIA to your Backend Systems is also connected to this Concept.
To offer a complete Frontend Solution, the Concept of a Session (and maybe even a loggedin User) is necessary. The Frontend API offers Endpoints to manage Sessions, Users and User Interactions. It should only be used in a Frontend Context, not within any Form of Backend Processing.