Left – right and double.
Your humble computer mouse (or tackpad) has been with us for many years but many people are still very confused as to what the buttons do and why you need 2?
The leftbutton is the action button, this button makes things happen. When you point at something on the screen and click the left button or you select the object or activate the object. This object could be an onscreen button, a scroll bar or a piece of text you want to highlight.
The right mouse button is the context button, pressing the right button brings up a menu that has information or functions that can be done to the object you clicked on with the left button (about if you like). An example would be to copy or paste the text you highlighted.
So when do you double click, in truth only on the desktop (screen where all your icons are) there are very few other places that you need to double click. You only double left click there is no such thing as double right click.
Wheels, most mice have a wheel in the middle, this is used to make the page scroll up and down. If the page it too long to fit on the screen then a scroll bar is displayed on the right but its quite slow to move your mouse to the right side of the screen and keep repeatedly pressing to get the page to move down. Using the wheel is much easier and much faster.
Touchpads have similar functions, either using the far right hand side of the pad or by placing two fingers on the pad and pulling down or pushing up you can achieve the same as wheel on a mouse.