Well i always see it in popular games like if you resize your window screen the gui stays in the same position of the screen, but for my game the gui doesnt stay put!!!! it's really important, and ive been needing to know for a long time.
You use the Scale portion of the UDim2 for the Position property.
For example, this Frame will always be 25 pixels off from the lower right-hand corner:
local Frame = Instance.new("Frame", ScreenGui)--You'll have to define ScreenGui to actually use this code. Frame.Size = UDim2.new(0, 50, 0, 50) Frame.Position = UDim2.new(1, -75, 1, -75)