IP Addressing for Networking

Every computer on the Internet has a  unique IP address.Withe the help of that uniquely IP we identifies the device and found it from other computers on the Internet.IP address consists of 32 bit , often shown as 4 octets of numbers from 0-255 represented in decimal form instead of binary form.
 For Example the IP Address is                                192.168.1.125
                                                               11000000.10101000.00000001.01111101
       For human being it is easier to remember the decimal number rather then the binary code.Fot that reson we use the decimal to represent the ip address.but the binary represtation is important to detemine in which class this ip belong with.IP address always assigne according to class.i mean for ip addresses there is a standard that apply according to your requirement.IP classes define how many network ids and how many host this network actually has.

Now we discuse ip classes

Historically, RFC1700 grouped the unicast ranges into specific sizes called class A, class B, and class C addresses. It also defined class D (multicast) and class E (experimental) addresses, as previously presented. The unicast address classes A, B, and C defined specifically-sized networks as well as specific address blocks for these networks, as shown in this figure.

how we get the number of network and number of host per network.see the following table

Note: Class A addresses 127.0.0.0 to 127.255.255.255 cannot be used and is reserved for loopback and diagnostic functions.