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Agent-based systems
Agent-based systems have two different components: a server, and a client called agent.
There is only one server, and it contains all of the configuration for your whole environment, while the agents are as many as the machines in the environment.
In some cases, more than one server could be present to ensure high availability, but treat it as if it's a single server, since they will all be configured in the same way.
Periodically, the client will contact the server to see if a new configuration for its machine is present. If a new configuration is present, the client will download it and apply it.