Each and every system on the internet is identified using a unique address called as IP Address. IP addresses are represented in dotted decimals. Since computers can understand only in binary format, the IP address will consists of 1’s and 0’s.

Class C IP Address:

Class C IP’s are used for business purposes. The business process should be small or medium sized. The first octet starts at 192 and ends with 223. The second and third octets are used as Net Identifiers. The Last octet is used as the Host Identifier. 110 is the first three bit values of the first octet.

110nnnnn nnnnnnnn nnnnnnnn hhhhhhhh

is the representation of Class-C IP Address. There can be 254 hosts on each Class C.

Class D IP Address:

Class D IP Addresses are used for multicasting. 1110 is the first four bits of the first octet. The left 28 bits are used to identify the group of systems to which the multicast message has to be sent. It differs from the other 3 Classes by the technique of multicasting.

1110mmmm mmmmmmmm mmmmmmmm mmmmmmmm

is the representation of Class-D IP Address. The Octet starts at 224 and ends at 247.

Multicasting is nothing but the process of sending a same message to a group of systems.
This is common in business processes when partners are connected together and are in need to share the same information at the same time.