1. Alternatively referred to as a heap allocation; when referring to computer memory, a dynamic allocation is the computer memory process of allocation and de-allocation segments of memory.
2. When referring to a network or network device, dynamic allocation or a dynamic IP address is the automatic assignment of an IP addresses by the network. For example, an IP addresses being assigned by DHCP.
Setting up a network with DHCP is much easier to control and setup then manually assigning every computer and device with a static IP address. However, because the IP address for a user can change this may cause issues if you rely on services that verify a user based off their IP address.