The Free On-line Dictionary of Computing (30 December 2018):

IP address
Internet address
IP number

    (Internet address) The 32-bit number uniquely
   identifying a node on a network using Internet Protocol,
   as defined in STD 5, RFC 791.  An IP address is normally
   displayed in dotted decimal notation, e.g. 128.121.4.5.

   The address can be split into a network number (or network
   address) and a host number unique to each host on the
   network and sometimes also a subnet address.

   The way the address is split depends on its "class", A, B or C
   (but see also CIDR).  The class is determined by the high
   address bits:

   Class A - high bit 0, 7-bit network number, 24-bit host
   number.  n1.a.a.a 0 <= n1 <= 127

   Class B - high 2 bits 10, 14-bit network number, 16-bit host
   number.  n1.n2.a.a 128 <= n1 <= 191

   Class C - high 3 bits 110, 21-bit network number, 8-bit host
   number.  n1.n2.n3.a 192 <= n1 <= 223

   DNS translates a node's fully qualified domain name to an
   Internet address which ARP (or constant mapping)
   translates to an Ethernet address.

   [Jargon File]

   (2006-01-27)