Understanding some concepts in JavaScript:

clientX sets or gets the x-coordinate of the mouse pointer position relative to the client area of ​​the window, where the client area does not include the window's own controls and scroll bars.

clientY sets or gets the y coordinate of the mouse pointer position relative to the client area of ​​the window, where the client area does not include the window's own controls and scroll bars.

offsetX sets or gets the x coordinate of the mouse pointer position relative to the (this) object that triggered the event.

offsetY sets or gets the y coordinate of the mouse pointer position relative to the (this) object that triggered the event.

screenX Sets or gets the x coordinate of the mouse pointer position relative to the user's screen.

screenY sets or gets the y coordinate of the mouse pointer position relative to the user's screen.

x Sets or gets the x pixel coordinate of the mouse pointer position relative to the parent document.

y Sets or gets the y pixel coordinate of the mouse pointer position relative to the parent document.

As shown in the picture: The picture comes from the Internet