The actual difference, from the point of view of someone not contributing code to either project?
Wayland is newer code, and provides better support for some hardware features of more recent origin like HiDPI. Because it’s newer, it can be a bit buggy/flaky sometimes, but it seems to be past the worst of that now and works well enough for many people. On modern hardware, it will probably provide a marginally better visual experience for someone who’s paying close attention to details like animation smoothness (stuff that I personally don’t care about).
X is older, more stable, and has certain core features (X forwarding, for instance) that Wayland prefers to leave for third-party software to implement. It’s also a child of an earlier era, and wasn’t designed with the expectation that it would be under attack 24/7 by malicious actors from around the world. The codebase, like those of many other older pieces of software, contains a certain amount of cruft and miscellaneous technical debt, and between that and the fact that X isn’t adding new! shiny! features, it’s harder to get coders to work on it. I’ve always found it to be solidly reliable provided that it’s being used in the sort of environment that was most common until recently (a single largish screen of <100dpi resolution with a constant refresh rate).
The actual difference, from the point of view of someone not contributing code to either project?
Wayland is newer code, and provides better support for some hardware features of more recent origin like HiDPI. Because it’s newer, it can be a bit buggy/flaky sometimes, but it seems to be past the worst of that now and works well enough for many people. On modern hardware, it will probably provide a marginally better visual experience for someone who’s paying close attention to details like animation smoothness (stuff that I personally don’t care about).
X is older, more stable, and has certain core features (X forwarding, for instance) that Wayland prefers to leave for third-party software to implement. It’s also a child of an earlier era, and wasn’t designed with the expectation that it would be under attack 24/7 by malicious actors from around the world. The codebase, like those of many other older pieces of software, contains a certain amount of cruft and miscellaneous technical debt, and between that and the fact that X isn’t adding new! shiny! features, it’s harder to get coders to work on it. I’ve always found it to be solidly reliable provided that it’s being used in the sort of environment that was most common until recently (a single largish screen of <100dpi resolution with a constant refresh rate).