Some nomenclature used to describe prefixes:

  • This is an address since it has no associated mask

  • This is a prefix.

  • This is a host prefix (the mask length is the size of the address).

Prefix A is more specific than B if its mask length is longer, and less specific if the mask is shorter. For example, is more specific than A less specific prefix that overlaps with a more specific is the covering prefix. For example, is the covering prefix for and is termed the covered prefix. A covering prefix is therefore always less specific than its covered prefixes.