You have DHCP set up on your network. You want the DHCP server to issue an IP address to the network printer but you don’t want that address to change. What type of DHCP address assignment is being used?
A DHCP reservation is the process of binding an IP address to the MAC address of a device so that address is permanently assigned to that device and will not be reissued by the DHCP server. It is a helpful alternative to assigning a static IP directly on the printer, allowing you the same functionality but centrally managed on your DHCP server.
Wikipedia
The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol (IP) networks for automatically assigning IP addresses and other communication parameters to devices connected to the network using a client–server architecture.The technology eliminates the need for individually configuring network devices manually, and consists of two network components, a centrally installed network DHCP server and client instances of the protocol stack on each computer or device. When connected to the network, and periodically thereafter, a client requests a set of parameters from the server using DHCP.
DHCP can be implemented on networks ranging in size from residential networks to large campus networks and regional ISP networks. Many routers and residential gateways have DHCP server capability. Most residential network routers receive a unique IP address within the ISP network. Within a local network, a DHCP server assigns a local IP address to each device.
DHCP services exist for networks running Internet Protocol version 4 (IPv4), as well as version 6 (IPv6). The IPv6 version of the DHCP protocol is commonly called DHCPv6.