[General Maximus]

The organization that doles out IP addresses to the world reserves a range of IP addresses for private networks. Private networks can use IP addresses anywhere in the following ranges:
•192.168.0.0 - 192.168.255.255 (65,536 IP addresses)
•172.16.0.0 - 172.31.255.255 (1,048,576 IP addresses)
•10.0.0.0 - 10.255.255.255 (16,777,216 IP addresses)

The assumption is that these private address ranges are not directly connected to the Internet, so the addresses don't have to be unique. In today's world, these private address ranges are often used for the protected network behind network translation devices.

Because the private address ranges in a network don't have to be synchronized with the rest of the world, the complete address range is available from any network. A network administrator using these private addresses has more room for subnetting, and many more assignable addresses.

http://whatismyipaddress.com/private-ip