APIPA allows a computer to assign itself an IP address in the absence of a DHCP server. It is a feature of Windows operating systems and uses a designated range of addresses, from 169.254.0.1 through 169.254.255.254. The computer will randomly choose an IP address within this range, allowing for basic network communication within the local network. This is only meant as a temporary solution until a DHCP server can be reached. The other ranges provided are used for other purposes. The 192.168.x.x range is commonly used for private networks, where the IP addresses are manually assigned or assigned by a DHCP server. The 127.0.0.x range is reserved for loopback addresses, which are used for network software testing on the local machine. The 255.255.255.x subnet mask is not an IP address but is used to define the size of the network.