An IP or ‘Internet Protocol’ is the way in which data is sent from one device to another over the internet. The Internet Protocol is responsible for addressing hosts and for routing datagrams (packets) from a source host to a destination host across one or more IP networks. Within the task of delivering information from the source host to the destination host an IP has two jobs. Firstly the IP defines the format of packets that are to encapsulate the data to be delivered. Secondly the IP provides an addressing system that has two functions: identifying hosts; and providing a logical location service.
Each computer or otherwise known as a ‘host’ has at least one unique IP Address, similar to the way that every house has a street address. IP address stands for an ‘Internet Protocol’ Address. An Internet Protocol address or IP address is a 4 digit numerical label that is assigned to each device that participates within a computer network using internet protocol communication (The Internet). For example it is an address that is attached to your computer or phone that then allows you to be located the same way that an address is attached to your house.
There are two different ways that a network can be set up with IP addresses.
Private – On a private network a single body controls the assignment of the addresses for all devices. The organization has pretty much full control to do what they wish in regards to assigning IP addresses as long as each address is unique.
Public – In contrast, on a public network a mechanism is required to ensure both that organizations don’t use overlapping addresses and also to enable efficient routing of data between organizations. The best-known example of this is of course the Internet, where public IP registration and management facilities have been created to address this issue.
There are also advanced techniques now such as IP Network Address Translation that allow a network using private addresses to be interfaced to a public TCP/IP network. This works in a similar way to that of an apartment building. The building itself is given a single street address such as 120 Broad Street. All private apartments within that building are also given an individual address for example 15/120 Broad street. Imagine if every household had a single number address rather than the use of postcodes, street names and the street numbers. The complexity of locating a specific house would become ridiculous, hence the use of network address translation.