(If you want to know some more cool tricks check out our 10 Windows 10 Tips tutorial.)
What does it do? It allows you to switch between programs. So it could be the case that you're working on Outlook, and you need to quick view your spreadsheet. I can imagine it right now like some sort of nightmare. I'm in the training room and we need to quickly switch to an already opened Google page. I then hear the dreaded sound of the mouse clicking on the task bar.
However sometimes I do hear a sound that brings a smile to my face . It's the sound of keyboards. The sound of someone holding down the Alt key and pressing the tab key. It's the sound of them doing that with their left hand. Also the sound of students repeatedly pressing the tab key while holding down the Alt key until they get to their window of choice.
Yes, sad to say that one of my pleasures in life is that Alt Tab combination.