Internet tips -> What is IP Address? What is DNS?
For one computer to connect to another computer and transfer information, the IP address of that computer should be known. This IP Address is made of numbers. The 32 Bit IP address is divided into 4 sections of 8 bits each separted by a '.' (dot). Each 8 bit is called an Octet. The value of each Octet will vary between 0 to 255.
For example, 126.96.36.199 is an IP address. As you can see there are four sections each separated by a dot.
Name Vs Number
If someone asks you whose phone number is 98343453 you may not know it. But instead if someone asks you whether you know 'John peters' immediately you will remember your friend. The reason is names are easier to remember than numbers. This is human nature.
In internet, there is a need to connect to a lot of different computers daily. If you have to remember the IP address of each computer in the internet, it is impossible. Because IP Address is made of numbers.
That's why, computer scientists decided to give a name to each of these IP addresses. These computer names that represent IP addresses are called 'Domain Names'. For example, www.yahoo.com is a domain name. It is easy to remember a name. Isn't it?
Every computer that connects to the internet has a unique IP Address. Most of the computers especially servers will have a domain name.
DNS - Domain Name System
If you need to connect to a computer in the internet, you can use the IP address of that computer or the Domain Name of that computer.
But the computers need just the IP addresses. For our own convenience we use domain names. Therefore when we use the domain name, for example www.yahoo.com, our computer will first find out the IP address of this domain name and then uses the IP address to connect to it.
Let us assume that the IP address of the computer that you want to connect to is 188.8.131.52 and the domain name of this computer is www.xyz.com .
Now you connect to Internet, open your browser and key in the IP address 184.108.40.206 in the address bar and 'Enter'. The browser will immediately connect to the computer because the computer knows how to use the IP address.
Now imagine that you typed the domain name www.xyz.com instead of the IP address in the browser. What the computer needs is the IP address not the domain name. Therefore the browser will try to find the IP address for the domain www.xyz.com . For this purpose it will contact the DNS (Domain Name System) server. The DNS server will find the IP address of that domain and will return the IP address to your browser. Then your computer will use that IP address to connect to that computer.
If you type the IP address, the browser will access that site immediately. If you type the domain name, there will be slight delay because the browser has to connect to DNS server first to determine the IP address. If for some reasons this DNS server is down or there is not DNS entry for that domain, then that domain name or website address will not be accessible.