Hopefully this is clearer:
Current Behavior: Some web browsers, like Firefox and Chrome, allow the side buttons on a mouse, typically controlled by the thumb, to act as "back" and "forward" buttons for navigation. These are buttons four and five.
Problem: These side buttons can unintentionally simulate a middle mouse button click. This can be frustrating because it might open extra tabs when you accidentally click them while hovering over a link or a large image acting as a link.
Issue with Extensions: Additionally, this behavior can interfere with browser extensions, such as autoscroll. Autoscroll scrolls the browser when the middle mouse button is clicked and the mouse dragged up or down. Currently these side buttons also emulate this middle mouse button as well as the back and forward functionality.
Proposed Solution: To align with the behavior in Firefox and Chrome and enhance the user experience, the suggestion is to add an option in the browser's preferences. This option would let users prevent the side mouse buttons from simulating clicks and opening extra tabs.
Result: By implementing this feature, the side mouse buttons will work just like in Firefox and Chrome, exclusively performing back and forward operations without triggering unintended actions in the browser