Understanding Apache's access log

Question

What do each of the things in this line from my access log mean?

127.0.0.1 - - [05/Feb/2012:17:11:55 +0000] \"GET / HTTP/1.1\" 200 140 \"-\" \"Mozilla

Answer 1

I also don't under stand what the "-" means after the 200 140 section of the log

That value corresponds to the referer as described by Joachim. If you see a dash though, that means that there was no referer value to begin with (eg. the user went straight to a specific destination, like if he/she typed a URL in their browser)