DNS is mostly a directory service. Millions of people and computers use one or more directories every day. Currently, so many directories exist in our world that they have become almost transparent to casual observers. You could say it's a directory kind of world out there and DNS remains a big part of it for people who use the Internet regardless of the device.

In the old days, people often referred to directories as databases and technically they were right. Directories and databases share many characteristics such as the storing of information and the ability to rapidly search through that data. Think of how many times you use your cell phone as a database for personal contacts. In fact, your cell uses its address book as a directory to rapidly find and dial people's telephone numbers.