Basic Questions from a "Never Played No-Limit" Nube

[12AX7]

Can someone give me a quick run down on what the structures mean? For example, what does $2/$5 No-limit $200 buy in mean?

I thought "no limit" meant "no limit" LOL!

Also is no limit the way to go online? I've read most of the fancy tracking software hasn't been applied to it yet?

Lastly, I've also read that this is currently where the most profit is on the Vegas Scene these days too. One article writer wrote what I saw, 5 years ago... that before WPT Vegas Poker rooms were dying. Now the old Vegas Rocks are rolling in dough playing $2/5 "no limit".

Anyway, a any comments or good things to read would be appreciated.