To take care of this, we have a centralized authority known as Internet Assigned Numbers Authority (IANA), which is responsible for assigning a unique number known as an IP (Internet Protocol) address. An IP address is a 32-bit binary number that is divided into four octets and each octet contains 8 binary digits and these octets are separated by a dot (.). An example of an IP Address is as follows;

11110110.01011010.10011100.1111100

Each 8-bit in an octet can have two binary values i.e., 0 and 1. Therefore, each octet can have a minimum value of 0, i.e., 00000000 to a maximum value of 256 i.e., 11111111, and in total have 28 = 256 different combinations.

Again to remember this 32-bit address in binary is a bit difficult, so for a better understanding of human beings, it is expressed in a decimal format. But this decimal format is for human understanding only and the computer understands it in binary format only. In decimal, the above IP address is expressed as;

123.45.78.125

These octets are used to create and separate different classes. An IP address consists of two parts viz. Network and Host. The network part identifies the network different networks and the host part identifies a device of a particular network.

The address uniquely identifies a device connected to the internet similar to the postal system where we identify any house by first identifying the country, then state, district, post office, cluster/block, and finally the house number. These IP addresses are classified into five categories based on the availability of IP range. These categories or classes are;

IANA decentralizes the task of assigning IP addresses by allocating a large chunk of IP addresses to five Regional Internet Registries (RIRs), which are further responsible for allocating to the IP addresses in their zone. These RIRs along with their area of operations are listed below;

• APNIC- This RIR is responsible for serving the Asia Pacific region
• AfriNIC- This RIR is responsible for serving the African region
• ARIN- This RIR is responsible for serving North America and several Caribbean and North Atlantic islands
• LACNIC- This RIR is responsible for serving Latin America and the Caribbean, and
• RIPE NCC- This RIR is responsible for serving Europe, the Middle East, and parts of Central Asia

For liaison and coordination between these five RIRs, there is an organization called Number Resource Organization(NRO).