How to combine a lib file with a project?

Question

C++ / C#

Hello
After building someone else's library from the source code, a file with the .lib extension appeared.
What to do with it is not clear, because only .a files lie in the lib folder of the compiler. Please tell me what needs to be done to make it work.

Answer 1

After building someone else's library from source code, a file with the .lib extension appeared

Traditionally static libraries are named *.lib on Windows and *.a on *nix. The dynamic libraries are named *.dll and *.so, respectively.
Pass to the linker. It doesn't matter what it's called.