Lua is used to make some games.
Example code is:
local player = game.Players.LocalPlayer
'Players' is all players.
'LocalPlayer' is just a player. Each player separated.
This shows a variable.
So If I were to type in:
local items = player.StarterGear
It would mean items is the gear you ('player') start with.
Go to wiki.roblox.com/?title=Scripting, it talks about it.