I've seen people do things like
mouse.hit.Position
and then I have seen people do things like
mouse.hit.P
Whats the difference? Also if I was trying to find it with a server script using invokes, would I send the mouse or Mouse position?
Mouse.Hit is a CFrame, so really you're asking if there's a difference between CFrame.Position or CFrame.p. As for that, in the CFrame documentation only .Position is referenced explicitly in properties, .P is only referenced in two methods in their descriptions. So if you wanted to be proper I'd say use .Position, as someone looking up .P might not have an idea of what you're referencing, and the documentation wouldn't help them unless it gets updated in the future.