Can someone explain to me the difference between starter gui and player gui?

The roblox wiki contains documentation, but since im too lazy to look it up, here is how they work

The StarterGuiis where you put all the GUI's you want players to spawn with when they join/respawn.

When a player joins/respawns, all the GUI's in StarterGuiare cloned and put into the player's PlayerGui

StarterGuiis a container, and for that reasons all scripts inside the StarterGuiwill not execute until they

are cloned into the PlayerGui

The children of StarterGui are sent to every new player's PlayerGui when they join the game and the children are then reset upon death (the children are sent again, unless you set this to true (can be found in StarterGui):

ResetPlayerGuiOnSpawn

Every player has a PlayerGui, they are used to store ScreenGui's to show GUI's to the player.

You can find more information on the wiki:

http://wiki.roblox.com/index.php?title=API:Class/StarterGui http://wiki.roblox.com/index.php?title=API:Class/PlayerGui

All the best, if you need more information then feel free to leave a comment.

whatever is in the startergui gets cloned to a players playergui when they spawn