An IP address that is used on a private TCP/IP network that is isolated from the Internet.
an address used on a local network. These addresses cannot be reached directly over the internet because the routers on the internet cannot route them. The common private addresses are 192.168.?.? and 10.?.?.? with most organizations using the former. These may also be called Non-routable addresses.
An Internet Protocol address that is available for us on any network; however, it is not routable on the Internet. Private IP addresses are used extensively in networking due to a shortage of public IP addresses. Network address translation (NAT) is used to connect and route private IP addresses onto the Internet. A private IP address can be referred to as a "fake" or "foreign" IP address.