What is an IP address?
Every device connected to the public Internet is assigned a unique number known as an Internet Protocol (IP) address. IP addresses consist of four numbers (also called octets) separated by periods (also called a 'dotted-quad') and look something like 127.0.0.1.
Since these numbers are usually assigned to internet service providers within region-based blocks, an IP address can often be used to identify the region or country from which a computer is connecting to the Internet. An IP address can sometimes be used to show the user's general location.
Because the numbers may be tedious to deal with, an IP address may also be assigned to a Host name, which is sometimes easier to remember. Hostnames may be looked up to find IP addresses, and vice-versa. At one time ISPs issued one IP address to each user. These are called static IP addresses. Because there is a limited number of IP addresses and with increased usage of the internet ISPs now issue IP addresses in a dynamic fashion out of a pool of IP addresses (Using DHCP). These are referred to as dynamic IP addresses. This also limits the ability of the user to host websites, mail servers, ftp servers, etc. In addition to users connecting to the internet, with virtual hosting, a single machine can act like multiple machines (with multiple domain names and IP addresses
More Information relating to IP Addresses
Domain Name Server (DNS):
This allows the IP address to be translated to words. It is much easier for us to remember a word than a series of numbers. The same is true for email addresses.
For example, it is much easier for you to remember a web address name such as datatechuk.com than it is to remember 126.96.36.199 or in the case of email it is much easier to remember email@example.com than firstname.lastname@example.org
Dynamic IP Address:
An IP address that is not static and could change at any time. This IP address is issued to you from a pool of IP addresses allocated by your ISP or DHCP Server. This is for a large number of customers that do not require the same IP Address all the time for a variety of reasons. Your computer will automatically get this number as it logs on to the network and saves you the trouble of having to know details regarding the specific network configurations. This number can be assigned to anyone using a dial-up connection, Wireless and High Speed Internet connections. If you need to run your own email server or web server, it would be best to have a static IP.
Static IP Address:
An IP address that is fixed and never changes. This is in contrast to a dynamic IP address which may change at any time. Most ISP's offer a single static IP or a block of static IP's for an additional charge per month.
IP version 4:
Currently used by most network devices. However, with more and more computers accessing the internet, IPv4 addresses are running out quickly. Just like in a city, addresses have to be created for new neighbourhoods but, if your neighbourhood gets too large, you will have to come up with an entire new pool of addresses. IPv4 is limited to 4,294,967,296 addresses.
IP version 6:
The replacement for the aging IPv4. The estimated number of unique addresses for IPv6 is 340,282,366,920,938,463,463,374,607,431,768,211,45 so hopefully when the internet switches over to IPv6 it should be a very long time before we run out of these!