An IP (Internet Protocol) address is a unique number which electronic devices use to identify and communicate with each other on a computer network. This address is determined by using the IP (Internet Protocol) standard. In simpler terms, the IP address is your computer's address on the Internet. Hence, it is unique to each device.

Apart from computers, the devices which can have their unique IP address include routers, switches, infrastructure servers, printers, Internet fax machines, and even some telephones.

IP addresses are assigned and managed by the IANA (Internet Assigned Numbers Authority). The IANA allocates blocks to any of the 4 regional Internet registries (ARIN, RIPE NCC, APNIC, and LACNIC) who then assign smaller blocks to Internet Service Providers and enterprises.

A typical IP address consists of 32 bit or 4 byte addresses and are usually represented by four numbers (each ranging from 0 to 255), which are separated by a dot. For example, it would look like ''. Each range of numbers between 0 to 255 usually can be represented by 8 bits, and so it is also referred to as an 'Octet'.

However, the limitation of this version is that the number of IP addresses is limited to 4,294,967,296 possibilities. So, a new classless scheme of IP address assignment called CIDR is replacing this method. This method is also tied into the next version (IPv6) of IP addresses.

The new version would include addresses which are 128 bits or 16 bytes wide, thus enabling an enormous magnitude of addresses to become available to computers on the Internet.


There are two types of IP addresses: Static and Dynamic. When the IP address of a computer remains the same every time it connects to the network, then it is called a Static. However, if it changes every time the computer connects to the network, it is referred to as dynamic.

What is my IP address?

By now you must be curiously wanting to find out your own IP address. Well, it is not difficult at all. However, the methods differ from situation to situation. Here are some simple methods to find IP address of your computer when on the Internet, when using a Macintosh computer, or when using a Windows computer, and even how to detect IP address of a received e-mail.

When on the Internet
There are a variety of websites on the Internet which can and do detect IP address of the computer when it is connected to the Internet. However, if you are on a LAN or a home network, then these websites may just be detecting the network router IP address.

When using a Macintosh Computer
On a Mac, the IP address is found in the TCP/IP control panel, while on a Mac OS X machine the IP address is found in System Preferences, in the section 'Internet and Network'.

When using a Windows Computer
On a Windows machine, the process is quite simple:
  • Click on the 'Start' menu button on the Windows taskbar.
  • Click 'Run'.
  • In the text box, type 'cmd'. This will launch a command prompt menu.
  • In this menu, type 'ipconfig/all'.
You will find your computer's IP address in the relevant field.

Detect IP address in received e-mail
If you want to detect IP address of the computer from which you have received an e-mail, you can find it in the e-mail header. Usually, this information is disabled from viewing. If you click on 'Show Headers' while viewing your e-mail on the Internet, you will be able to see the IP address of the computer from where the e-mail was sent.

IP addresses are also useful for detecting and solving cyber crimes and Internet based frauds and thefts such as phishing. They are also useful to track down spam or unsolicited e-mail, or when you have received malicious e-mails, e-mail threats, and viruses via e-mail.