What are linux long term support kernels?

I'm running an arch linux server and recently switched to an lts kernel from the repositories. Since I'm not rebooting the server very often, I want a stable kernel that is supported for a very long time. However, I noticed this specific arch linux lts kernel keeps getting updates. Some weeks ago I had installed the kernel 4.4.11 and now already a 4.4.12 update comes in. Being surprised about the 'high' update rate on the lts kernel track, I checked kernel.org and it states the latest longterm kernel is already 4.4.13, so I guess I have to update soon again on my server. The linux.com blog states , that the 4.4 kernel will be maintained for at least 2 years. But since there are already 13 updates (as in 4.4.13) in the last 5 months I don't really see the benefit of the long term support kernel. With such a high update frequency I could also run my server on the latest stable kernel and I would be not much more busy with updates than on the lts track. So, please explain me, what is the LTS kernel exactly designed for?