Please help? I am a beginner and I don't understand what local parent = part.Parent means

I take it this is inside a .Touched event function. What the script does is check if the part that triggered the touch event belongs to a player, and therefore can be used to run code only when a player touches something.

part refers to the block triggering the touched event. If this is a players arm, head, torso, etc., part.parent will then refer to the character (model group) in the workspace. This next function game.Players:GetPlayerFromCharacter(parent) will either return the corresponding player object in game.Players or nil, which will evaluate to true or false respectively in an if statement.