Is there a difference between s'il the plait and s'il vous plait
S'il te plait (forgive the missing circonflex "^") is the informal version of please: Meaning you would use this form when speaking to family; brothers, sisters, ect. Also when speaking with close friends.
S'il vous plait is the formal version of please: Meaning you would use this version when speaking with strangers, mostly adults or those that are quite a few years older than you. So, you can think of that form as the "polite" form, and if your in doubt of which form to use, proceed with "S'il vous plait."
Usually, adults will speak the same way with you, and after a while, if you hear them use the informal version when speaking with you, that is a sign that you can start doing the same with them.
Edit to my previous comment: "and if you're in doubt of which form to use, proceed with S'il vous plait."
"S'îl te plaît" is used to talk to one person, while "S'îl vous plaît" to multiple.