Education and Training
The first thing to look at (no pun intended) is the display—the centerpiece of any AIO. While some less-expensive AIO PCs will come with panels smaller than 23 inches, those are better suited to exceedingly cramped spaces such as classroom labs or dorm rooms. (Go much smaller than that, and you might as well just buy a big-screen laptop.) What you really want is a display at least 23 inches on the diagonal—and larger is better if you can do it. The biggest all-in-ones we've seen to date have curved 34-inch screens.
With a screen 23 inches or larger, you are almost guaranteed a native resolution of at least 1,920 by 1,080 pixels, and larger screens will go even higher. In many cases, that's up to 4K—3,840 by 2,160 pixels—for a conventionally shaped screen, or 3,440 by 1,440 pixels on an ultra-wide display. High resolutions of that kind give you the ability to view multiple windows side by side, or view a spreadsheet three to four pages wide. Indeed, if you are a multitasker, the more screen room, the better.