The dhcpd service acts as a DHCP server for clients.
Clients may solicit an IP address (IP) from a DHCP server when they need one. The DHCP server then offers the "lease" of an IP address to the client, which the client is free to request or ignore. If the client requests it and the server acknowledges it, then the client is permitted to use that IP address for the "lease time" specified by the server. At some point before the lease expires, the client must re-request the same IP address if it wishes to continue to use it.