Is it possible for me (admin) to download all student activity for an individual student into a zip file?
Well not easily I think- you might get a better answer if you post in the Using Moodle forums where they give more technical help - this is more for social chat. AFAIK you can get logs of student activity and you can download their assignments but it won't all come neatly into one zip file.
Dear Mary - you had me reaching for a Glossary then
http://www.email-software.org/email-acronyms.htm
IMHO, if we keep this up a Block in Moodle might be necessary....