public sealed class Sandbox.SpawnPoint : Sandbox.Component

Your games will likely want to react to people joining and leaving the game. To help with this you can implement Component.INetworkListener or Component.INetworkSpawn on a component and place it in the scene.

The networking system in s&box is purposefully simple and easy. Our initial aim isn't to provide a bullet proof server-authoritative networking system. Our aim is to provide a system that is really easy to use and understand.

To make a multiplayer game you need to take care of a few things. There's a special component that helps with those things, called NetworkHelper. This is a simple component that fits a lot of situations, but can be used as an example to code your own network component.