A proxy sits in front of several Minecraft servers and makes them look like one address. Players connect to the proxy, and it hands them to whichever backend they should be on — without ever disconnecting them.
What it buys you
Players move between servers without leaving the game. A lobby, a survival world, a creative world and a minigame can all live behind one address, and switching is instant instead of a disconnect and reconnect.
It also means you can restart one backend without kicking everyone off the network — they get bounced to the lobby instead of to the multiplayer menu.
Do you need one?
| Situation | Verdict |
|---|---|
| One survival world with friends | No. A proxy adds moving parts and solves nothing you have. |
| A survival world plus a creative world | Probably not. Multi-world plugins handle this inside one server. |
| Separate game modes that need separate plugin sets | Yes. This is what proxies are for. |
| You want a lobby with portals to other servers | Yes. |
| You want to restart one part without dropping everyone | Yes. |
What it costs
Every backend is a separate server process with its own memory. A proxy network of four servers needs the memory of four servers, plus a little for the proxy itself. That is what splitter slots are for — running several instances under one plan.
Backends must be configured to only accept connections that came through the proxy. Getting that wrong lets players connect directly to a backend and bypass authentication entirely. There is an article on it in the security section, and it is not optional.
Velocity is the modern option: faster, actively developed and with better forwarding security. BungeeCord still works and much of the internet still writes about it, but new networks have little reason to start there.