Should the web server be separated from the server application?

Question

client-server

Hello!
There is a website (back-end + front-end) and integration of the following functionality is required:
On the client side there will be a small Desktop application that needs to communicate with the main application. And the site acts as something of an interface. The user makes manipulations on the site, and the desktop application receives signals from the server and performs the work.
So tell me, in what situations should you write two different servers (one for the site, the other for the application), and when can you shove everything into one program? What are the rules of good taste and convenient development in this regard?
Please give a search vector, otherwise I lost my way :)

Answer 1

you need to write an API for the application ....