 You'll see most mechanical keyboards listed as having switches which are Cherry MX-compatible. This means they work with keycaps that have a cross-shaped socket, like this one. This standardized socket makes it easy to swap out your caps for another color, or shape, also known as keycap profile. There are several common keycap profiles with varied characteristics, ranging from DSA or XDA with a low uniform height, up to SA profile with tall caps of varying heights, or something in between, like the more common Cherry profile. The differing heights per row make the caps easier to reach from a central hand position. It's more ergonomic, but it means you can't really rearrange your caps if you want to say try a Dvorak layout.