How does the Linux file structure work?

Question

I see the different folders bin, dev, mnt, proc, srv, sys, etc.

What are the properties of all these different folders? What are their purposes? Are there files in some of them that I should not touch? Should I be touching files in the other folders?

Final question: in a Unix environment, do folders == directories? I apologize for all the questions.

Answer 1

Filesystem Hierarchy Standard: http://refspecs.linuxfoundation.org/fhs.shtml

GNU coding standards: http://www.gnu.org/prep/standards/ also has policies on directory usage, and sometimes disagrees with FHS

"Folder" is a term used by Mac and Windows people to refer to directories. Using it in unix land makes you sound like a newbie who hasn't gotten oriented yet.