What is the difference between pure golang and web framework like beego for server side in Web?

Ah - there are many popular web frameworks in golang. But I think the confusion is: with Python, for example, django is like the clear winner. Whereas, in the go ecosystem, there are more options. Most adhere to stdlib for the most part so they’re (for the MOST PART) pretty interchangeable. And you can get pretty far with stdlib + a few helper functions since most of what you want from a web framework is routing and serialization/deserialization, the latter of which is part of the stdlib. See this comment I made about routing via convention using only stdlib. If you wanted to be completely barebones you could use something like that as a starting point.