Wayland is a Display Server Protocol, meaning it is a specification of how a program wanting to display something like a window communicates with another program, the display server, which handles drawing to the screen.

It matters because it vastly simplifies and modernizes display server infrastructure.

X is huge, with many parts from the 80s and 90s that were simply not needed today, creating a fully compliant X Server with all extensions was pretty much impossible, which is the reason pretty much only X.org existed as a full implementation.

Some benefits for users are no screen tearing, VRR and support for more complicated setups like having multiple monitors all with a different refresh rate, which was a pain in the ass on X but is no problem on wayland.

X is going to die, especially with the fact that frredesktop and the two big DEs, GNOME and KDE are working on it. Some distros come with wayland by default already.

Yes, X is actually going to die.

On top of what other said, the wayland project also maintains the wayland protocols repository which includes additional protocols that are approved by a "committee" that includes representatives from wayland protocol implementations (wlroots, kde , gnome , smithay etc). for example now they are working on color management.

There appears to be a consensus among people working on window manager implementations that X has to go and wayland is the future.

Wayland has technical benefits, if you want the nitty gritty details see this.

Basically X11 is bad IPC at this point.

Also be careful with what you read online, I see misinformation about it relatively often.

Explained by someone that doesn't know the technical side super well.

1: It's a new protocol for displaying. The main difference from X11, as I understand it, is a simplification of the stack. Eliminating the need for a display server, or merging the display server and compositor.

2: Some things impossible (or difficult) with X11 are much better supported in Wayland. Their not necessarily available, as the Wayland protocol is quite generic and needs additional protocols for further negotiation. Examples are fractional scaling & multiple displays with differing refresh rates.

Security is also improved. X11 did not make some security considerations (as it is quite old, maybe justifiably so). In X11 it's possible for any application to "look" at the entire display. In Wayland they receive a specific section that they can draw into and use. (This has the side-effect of complicating stuff like redshifting the screen at night, but in my experience that has fully caught up).

3: If you're interested, are in desktop application development (but I have no experience in that regard) or have a specific need for Wayland.

4: I think X won't die for a long long time if "ever". I'm not super familiar with desktop app development, but I don't think it requires more work to keep supporting X.

On the other hand, most of the complaints about Wayland I've heard were ultimately about support. At some point, when you're a normal user, the distro maintainer should be able to decide to move to Wayland without you noticing, apart from the blurriness being gone with fractional scaling.

In short, Wayland is a protocol for graphics.

It's somewhat similar to X, as its main purpose is the same, however the archivecture is very different, and Wayland is much simpler/barebone.

If X is going to die or not — only time will tell. For now it can be considered another competing standard.

I think this is the perfect post to bring up XWayland.

That being said, I haven't used it yet (so I can't comment on whether it works flawlessly)! Can anyone elaborate on their experiences with it? I'm curious on it and don't have my hands on a Linux machine at the moment

You’ve already gotten great answers on what Wayland is, but as far as who should care:

Mainly developers and users with niche workflows. People with NVIDIA cards should care a little as initially NVIDIA did not support Wayland, but NVIDIA drivers are catching up so this should continue to improve. Most users should just switch when their DE switches.

Great answers here. I'd just like to add that X and Wayland are not completing. In fact, most of the Xorg devs are the ones working on Wayland. You can find Wayland mentioned in the Xorg Foundation Website.

I don't know anything about Linux, but I believe they merged with the Yutani Corporation in 2099.

Wayland is the fancy new standard that never seems to stably work for me on any of my machines :( Thanks for letting me revert to X in the login screen, GNOME.