For example, opening the topmost Computers icon in the tree view on the left displays all computers in the currently active management domain (single server or name service), whereas the Computers icon at a given network level displays only computers that are defined on that network.
The Computers/Networks tool also uses dynamic network and subnetwork containers to represent sets of computers that have IP addresses that do not exist on any defined network or subnetwork in the current management domain.
For example, if there is a computer with an IP address of 115.131.12.171 defined in the hosts table in the current management domain, but the 115.131.12 subnetwork is not defined in the netmasks table, the Computers/Networks tool automatically creates a dynamic subnetwork with an IP address of 115.131.12.
There are two instances in which the Computers/Networks tool creates dynamic networks or subnetworks to display computers that are defined in the hosts table:
You can delete computers, static (real) subnetworks, and static networks see Deleting Computers, Subnetworks, and Networks), but you cannot delete dynamic networks or subnetworks because, technically, they do not really exist.