I donâ€™t want to call your phone. I want to call you. Why do I have to look in my phone book (whether in paper, on my phone or computer) to find your number? Why do I have to guess whether youâ€™re at home, at work, or in the car? Why do I have to try that number, and if you donâ€™t answer, leave a message? Why canâ€™t I tell my phone to â€œCall Joeâ€ and have my phone call you no matter where you are?
On the internet, when I want to go to Google, I donâ€™t first look up Googleâ€™s IP address in my address book. I just type google.com into my browser. The browser then connects to something called the Domain Name Service (DNS for short) which converts the URL google.com into the IP address 220.127.116.11 and then it connects to it.