Exporting Vars

Just a question that I looked all over this site for:
I know you can send Vars to an external source, but i’m not sure how and what restrictions there are. Say i have a input txtbox. Can i send that var to say like a TXT file so i can compile a list of names or something like that. I’m not really familiar with XML and dont have the time right now to read up on that one. Could someone please help me