Frenzation

When I'm not playing on my server I have to launch it again is there a way to have it online all the time even if there's no people on it? Thanks

When no one is online the server needs starting up can only me ( the maker of the server) start it up or Can other people start it up beacuse if like my friends to be able to play when I'm not online. If other people can start it up please tell me how. Thanks