As the title indicates, how does Lemmy work?

I recently inquired in a couple other communities about necessities (whether it be hardware or software, ect) and guidance to create a server/instance and decided I may be better off understanding how this realm works and operates as my starting point, then move into the hardware side, then continue to the Sofware and setup.

  • What happens if an owner of an instance like u/spez goes crazy or shuts down his server for other reasons? Does this delete my user and content or can I move my account to another instance even if the server is already shut down?