A host joining an IPv4 network usually needs more than an IP address. It also needs parameters such as a subnet prefix, default gateway and DNS resolver.

DHCP supplies this configuration dynamically. A typical exchange follows four conceptual steps: the client discovers available servers, receives an offer, requests one configuration and receives an acknowledgement containing a time-limited lease.

Because a new client may not yet know its own address or the server's address, early DHCP messages can use broadcast delivery.

Leases let networks reuse addresses and update configuration without manually editing every host. Renewal extends a lease while the client remains connected.

DHCP is therefore a control protocol for host configuration. It does not route application traffic itself; it tells the host how to participate in the IP network.