Manual allocation – The server provides a specific IP address that you choose for a specific DHCP client. The address cannot be reclaimed or assigned to another client.
Automatic, or permanent, allocation – The server provides an IP address that has no expiration time, making it permanently associated with the client until you change the assignment or the client releases the address.
Dynamic allocation – The server provides an IP address to a requesting client, with a lease for a specific period of time. When the lease expires, the address is taken back by the server and can be assigned to another client. The period of time is determined by the lease time configured for the server.