Answer:
In a classic mouse, there are 3 buttons, left click, right click, and scroll wheel.
Step-by-step explanation:
If you have a more advanced mouse, however it may have 5 buttons. The 2 new buttons are back and forward. These buttons mainly apply to website where you can go back to the previous page you were on or return to the page you left. This is helpful since you don't have to move your mouse pointer all the way to the top of your screen and so you don't have to use the keyboard shortcuts, which in case you were wondering, is alt + left arrow to go back or alt + right arrow to go forward. There is also another button that you can use by pressing down on the scroll wheel. This button allows you to scroll through the page without having to constantly scroll down.