www.” in front of a domain so that you can view its website? “www.“ is actually a subdomain for the main domain and it was historically chosen as an acronym for “World Wide Web” or simply said, the website of that domain. Same as for the email, if the main domain doesn’t get found, then you usually can’t see the website anymore.
There are also other uses of the DNS which are even more hidden than the two mentioned above. Best example for such a service built on top of the DNS are white- and black-lists used to filter good and bad domains, respectively. A service makes a specially created query to a certain domain and get back an answer in form of an IP address (that’s what DNS does, right?). Many services use 127.0.0.1 for when the address is in the list and 127.0.0.2 when the address is not in the list.
Now you know exactly what DNS is used for and where. In our next part we will talk about what happens when DNS doesn’t work, so stay tuned!