An import is a specific C call to open a library, because you dont know
in advance what the "defines"/"functions" are in the library you cant
do it directly with an import.
Libraries typically contain a larger amount of functions for a specific area, much more than you would typically need in a specific application. Typically you import a a few functions but the library may contain hundreds.
Its like you city library, you just want to check out a few books but don't take the whole library home.
Only one instance of the library gets loaded on the OS, thats why they call it shared library. So even if you do several import statements you will load the library only once, or not at all, if another process on your machine has already loaded it.