I guess for the most part it's just marketing, since it's a good fit for IoT as well, you can definitely run it on servers as well, as i am doing!

What makes it different from other K8s distros is listed here: https://rancher.com/docs/k3s/latest/en/

And here's an architecture overview: https://rancher.com/docs/k3s/latest/en/architecture/

At a glance:

  - by default packaged as a single binary, so is extremely easy to install, even uses SQLite for storage (though that can be swapped out for others as well)
  - includes the functionality that you'd expect, like local storage, load balancing, ingress, while at the same time getting rid of some of the unnecessary plugins that you'd get in other distros
  - as a consequence of the above, has a small runtime footprint, so running K8s clusters on VPSes with 2 to 4 GB of RAM is no longer a pipe dream, also has way less overhead on the actual nodes that you want to manage (think along the lines of a few hundred MB)
  - also includes a variety of tools with it for managing your cluster more easily, so you don't need to install those separately