The simplest and most pragmatic answer is that this address is not routable, however, some argue that all IP addresses are routable, that is,  specific ranges of IP addresses is simply not publicly routed on the Internet. Instead, they are routed to a NAT gateway or a proxy server before being connected to the Internet.

Private IP addresses are used in most networks and small business because an ISP typically assigns a unique IP address to a location. If more than one device you need to connect to the Internet, NAT (Network Address Translation) gateway is used to connect to the Internet.

Most of the time, the NAT router device is also giving out private IP addresses to all computers on the local network.

Officially, there are three ranges of private IP addresses that have been defined by the IANA in RFC 1918:

IP Address Range Number of addresses Class - 16.777.216 A - 1.048.576 B - 65.536 C

Any private network in the world are using one of these IP address ranges to addressing scheme. The class is determined by the number of usable addresses in that range. Class A has more than 16 million usable addresses and only need for very large organizations with hundreds of interconnected networks.

The reason why most routers come setup with a class C IP address is because it can  handle more than 65,000 IP addresses, enough for almost any home or small business.

The first address that can be used in Class C network is, this  usually is configured in factory of routers. Note that if you want, you can change the default IP address either a Class B or Class A IP network and would still work fine.

Actually there is no difference between the different ranges of private IP, except for the available addresses.

How to find your router IP range?

For this purpose we use our available operating systems other than Windows 7, Linux Ubuntu 14.04(debian based) and Android