What are the most commonly used commands in Lua?

I'd like to know the commands for Lua. I already know functions, Connectives, and variables. But what about values, commands for connectives, commands for functions. Possibly other things I don't know about :P.

Each instance has it's own events (proper name of your "commands") but here is a complete link written by the ROBLOX wiki staff: ( http://wiki.roblox.com/index.php/Category:Events ) note like I said earlier each Instance has it's own set of events so .MouseEnter which is used for GUIs would not work for a Part. I recommend reading the wiki to see what each Instance has for it's events.