The answer is very simple:
Programming means writing human-like code which provides some functionality and then compiling this code to machine code or to lower code (ex. IL). Program needs to be written first, then compiled and then you can run it.
On the other side, scripting is writing code, which is supposed to run in program/interpreter/engine. Javascript (NodeJS), bash script, perl, python, ... these all are scripting languages because they don't need to be compiled, just called by interpreter.
Server side scripting is simply writing scripts for programs, which are evaluated on the server and doesn't need to be compiled.
ASP .NET is translated (compiled) into IL so that means it is server-side programming. If you have any other questions, I'll be happy to answer you.