what is a,b,c,d
and not understanding its representation
Ip adress classes
An IP address is a string of numbers separated by periods. IP addresses are expressed as a set of four numbers — an example address might be 192.158. 1.38 . Each number in the set can range from 0 to 255. So here
a–> 192, b–> 158, c–>1, d–> 38
It is just a representation to understand the concept.