Domain Name System or DNS is a hierarchical naming system for computers, services, or any resource participating in the Internet. It associates various information with the domain names assigned to each of the participants. Most importantly, it translates domain names meaningful to humans into the numerical (binary) identifiers associated with networking equipment for the purpose of locating and addressing these devices world-wide. An often used analogy to explain the Domain Name System is that it serves as the “phone book” for the Internet by translating human-friendly computer hostnames into IP addresses. Some companies take advantage of this and use it in some web blocking sites like OpenDNS to try and prevent their employees from visiting some sites, or even monitoring every activity within the network, but every intelligent web designers out there know that it is highly risky to make use of such sites because those sites have the ability to get in to every single activities within the network and they easily have the ability to hack in to the systems to get some vital information. It is highly advised that companies should refrain being too economical and make sure to buy those security software rather than making use of DNS blocking sites if they really love their business and they care for the future of their companies.