When a DHCP client and DHCP server are on different IP networks, which device forwards DHCP messages between them?

A DHCP relay agent is necessary when a DHCP client and server are on different IP networks. DHCP messages (like DISCOVER, OFFER, REQUEST, ACK) are broadcast messages and are typically confined to the local subnet. A router configured as a DHCP relay agent receives these broadcast DHCP messages from clients and then unicasts them to the DHCP server on a different subnet. The server's response is then unicasted back to the relay agent, which forwards it to the client. DHCPOFFER and DHCPDISCOVER are types of DHCP messages, not devices. The DHCP server processes requests but doesn't forward messages between different subnets itself.