This is one of the most confusing issues for users. Should I click, or tap, once or twice to initiate the action I want? Unfortunately, the short answer is that it depends.
The General Rule:
On a computer: one click will select something, and two clicks will open or run that thing.
On a phone or tablet: one tap will open or run the thing, and holding your finger down on the icon (a long tap) will select it.
Menu items always only require a single click.
Buttons always only require a single click.
In a web browser, like Chrome, Firefox, Safari, or Edge, most actions require only a single click.
On the task bar or dock, a single click will open the program, but on the desktop a double click is required to open a program or document.
In a word processing program like Microsoft Word, single clicking sets the text insertion point, and double clicking selects a word, while triple clicking selects the paragraph.
So go ahead and try a single click/tap first, and if that doesn’t do what you wanted, try a double click. Make sure to watch for signs that the program/page/document is opening, because continuing to click after the initial action has begun will only slow down the result and may actually perform additional actions that you are not expecting.