GUI Help: How to check for mouse actions?

Hi im new to unity3d and studying the GUI atm using the C# language.
I can not figure out how to script checks for “mouse hover” and “mouse clicks” using the GUI types such as GUI.Box, GUI.Button, and GUI.Label.

An example would be when a user hovers over a specific GUI.Box, the box RECT would move or change sizes.

I know the GUI.Button class returns a bool value in the function call but for clicks only and not hover. And the other GUI types have void functions. So i dont know how to script an If statement using the GUI types.

Can anyone help?

Thanks for the answer but i stumbled upon one problem in your code.
Input.mousePosition uses World Space(coordinates 0,0 start at bottom left screen).
GUI is based on Screen Space (coordinates 0,0 start at top left screen).

So by replacing Input.mousePosition with Event.current.mousePosition fixes that problem.

    public rect GUIArea;
 
if (GUIArea.Contains (Event.current.mousePosition)){
bMouseOverGUI = true;
}