What Is An IP Address?

Each device or interface (printers, routers, desktop computers, etc.) connected in a computer network is assigned a unique identifier to ensure it receives messages and information intended for it, much like a mailing address. Without a unique identifier, devices would not be able to receive messages in the same way that without a home address or a post office box, you would not receive snail mail. Most computer networks today, including the Internet, use the Internet Protocol (IP) address defined in the TCP/IP protocol suite.

Domain Name System (DNS): DNS translates the IP address to human-readable format: words. It’s easier for most people to remember words rather than a string of numbers. For example, it’s typically much easier for you to remember a web address name such as addrex.net than it is to remember 192.168.1.1 or in the case of email it is much easier to remember [email protected] than [email protected].

Different IP Addresses

Dynamic IP Address: An IP address that is not static and could change any time. This IP address is given to you from a pool of IP addresses allocated by your Internet Service Provider (ISP) or Dynamic Host Configuration Protocol (DHCP) server.  Dynamic IP addresses are used for a large number of customers that don’t require the same IP address all the time. With a dynamic IP address, your computer will automatically get an IP number as it joins the network and save you the trouble of having to know the details about your computer and network configuration.  Dynamic IP addresses are typically assigned to anyone using dial-up connection, and wireless and high speed internet connections. However, if you need to run your own email server or web server, it’s better to have a static IP address.

Static IP Address: An IP address that never changes and is fixed; in contrast, dynamic addresses may change at any time. Most ISP’s can assign a single static IP or a block of static IP’s for a few extra dollars a month.

Different IP address versions

IP version 4: Currently used by most network devices. However, with more and more computers accessing the internet, IPv4 addresses are running out quickly – IPv4 is limited to 4,294,967,296 or 2^32 addresses. Just like in a city, addresses are created for new neighborhoods.  However, if your neighborhood gets too large, you will have to come up with an entire new pool of addresses.

IP version 6: The replacement for IPv4, which has a much larger number of unique addresses – for IPv6, there are 340,282,366,920,938,463,463,374,607,431,768,211,456 or 2^128 addresses.

For additional information about the difference between IPv4 and IPv6, see our post that describes the difference in detail. (What’s the Difference Between IPv4 and IPv6 Addresses?)