IP addressing. Private (gray) and public (white) IPs

Private IP addresses are reserved for local area networks (RFC 1918): Class A: 10.0.0.0 - 10.255.255.255 (corporations, ISPs); Class B: 172.16.0.0 - 172.32.255.255 (universities, data centers); Class C: 192.168.0.0 - 192.168.255.255 (home).