Hi! Im new to self hosting. Currently i am running a Jellyfin server on an old laptop. I am very curious to host other things in the future like immich or other services. I see a lot of mention of a program called docker.

search this on The internet I am still Not very clear what it does.

Could someone explain this to me like im stupid? What does it do and why would I need it?

Also what are other services that might be interesting to self host in The future?

Many thanks!

EDIT: Wow! thanks for all the detailed and super quick replies! I've been reading all the comments here and am concluding that (even though I am currently running only one service) it might be interesting to start using Docker to run all (future) services seperately on the server!