/lobby command

I am currently building a server and I'm new to it. I have nearly built the lobby and I have set the spawn to the centre of it. If I type /spawn it works and I go to spawn but I have seen it on servers were you can type /lobby. Does anyone how I can change the command or add the command /lobby to take players to spawn. I would rather have /lobby than /spawn on my server. I hope hat makes sense