Need Help Understanding This Parameter

So im currently trying to understand the fundimentals of lua through the Roblox documations and i need help understanding how this “otherpart” parameter works.

The otherpart is the part touching the speedBoost

Otherpart is basically the part that came in contact with your “speedboost” part. As you can see, to confirm it was a player, you are looking for a humanoid which only a player possesses. However, you look through the otherpart’s parent as it’s not the character that directly touches the speedboost part, it’s a child of it (Head, rightleg etc). That’s what other part is, it’s a child of the character of the player