i have an older "All-in-one" Sony computer from the Pentium4 era that a friend gave me on my workbench with something called Fedora Linux on it as an operating system. The computer and widescreen monitor is all one unit and i just plug a USB keyboard+mouse to it; it has built-in ethernet, but I don't have a run of cable into the garage so I just use a wireless card in it; which is plenty enough for what i use it for in the garage.
I tend to use it to look up DIY info from either car forums or youtube when I need to fix something i'm not that familiar with. I also have links to a website that has BMW TIS and BMW part number stuff. so, it's mostly web browsing. I do have manuals for my cars, but i find it easier to search the internet 1st and then resort to finding a page in the manual. Or, if something doesn't look quite right, like a torque spec that just seems off, I'll double check it with multiple sources. when i'm fixing other people's cars, they some times use it to look up parts they need and place orders for stuff.
additionally, since the all-in-one has built-in speakers, i also use it to listen to online radio channels when i'm working on something for some background music... that count as a tool too? ;-D