# Glossary

### Archetype

Group of Components that define a type. Makes use of LODs.

### Client

Allows a User to interact with the World. Connects to Replication Server.

### Client connection​ <a href="#client-connection" id="client-connection"></a>

An object representing a client connected to the Replication Server. Required for the client messages.

### Client message​ <a href="#client-message" id="client-message"></a>

A message sent to a *client connection*.

### Command

Allows for sending an instruction to an Entity that may be running on a different machine.

### Component

Part of ECS. Describes a characteristic or aspect of an Entity.

### ECS

Stands for Entity Component System. An entity system where entities are made of components.

### Entity

An instance of an Archetype. Part of ECS.

### Live Query

Allows the Client to specify a subset of the World to receive updates from. Acts as a filter to exclude updates on less relevant entities that could otherwise result in undesired latency.

### LOD

A partial representation of an Archetype. Allows for specifying priorities of components within an Archetype.

### Protocol Code Generator

Generates the client schema source file (e.g. schema.cs) that automatically handles serialization/deserialization of an ECS world and commands.

### Replication Server

Replicates the state of the world to the connected Clients and Simulators.

### Simulator

Responsible for simulating a subset of the game world. Connects to Replication Server through which the state gets replicated to Clients.