alright so please no flaming me here. This is such a simple question

Im completely new to compilers/interpreters and have just started to take up learning python as a bit of a hobby

I have python27 installed and just started using the shell to learn.
I have noticed that I can't seem to write more than one line of code because every time I press enter it executes the line I just finished. then for shits and giggles I tried running the basic hello world from the cmd prompt and it asked what program to use to run it with.
I chose crimson editor as that is what I use for my site scripts. and it just showed the exact same things as the interpreter showed -> one line of code and the executed code.

How do I write multi-line code in the python shell without it running it everytime I press enter?
Why isn't it running from the cmd prompt?
I have completely overlooked something, I know. but this has never been my thing and its only recently I've tried to expand my thing, lol (not by whipping it against the bedpost or anything )