What is Bungeecord?
BungeeCord is used to link multiple servers together. It is not a standalone server and requires a minimum of 3 servers to work.
For example:
One Server (Bungeecord)
One Server (Lobby)
One Server (Factions)
Here's a diagram of how it works:

This article explains more about it: https://www.spigotmc.org/wiki/about-bungeecord/
For example:
One Server (Bungeecord)
One Server (Lobby)
One Server (Factions)
Here's a diagram of how it works:

This article explains more about it: https://www.spigotmc.org/wiki/about-bungeecord/
Updated on: 01/01/2019
Thank you!