What the Whitelist Does
When whitelist mode is enabled on your server, only players you have approved can connect. Everyone else receives a rejection message at the login screen. The whitelist is stored in a SQLite database (whitelist.db) on the server and managed through RCON commands, which the panel handles automatically behind the scenes.
Whitelist vs Password
A server password is simpler to set up - anyone with the password can join. A whitelist requires you to explicitly approve each player, giving you precise control over who is on your server. For community servers with an application or vetting process, a whitelist is the better choice. For a small group of trusted friends, a password is usually sufficient.