A dig utility allows you to make dig commands to a server. This is used for querying DNS name servers and is particularly useful for troubleshooting or just for educational services as a demonstration of how servers work.
dig (which is always written in lower case) can operate in interactive command line mode or batch mode by reading requests from operating system files. It is usually used for getting information about host addresses, nameservers, mail exchanges and a range of other related information. It can be used from Linux or Mac OSX operating systems and normally it is used to query just a single host.
dig is very useful for server maintenance professionals as well as web developers and webmasters that create and manage their own self hosted websites. There are many uses for dig but you can imagine it as a little mining trip where you are 'digging' for information.
This free online dig utility makes it very fast and simple to use dig. It runs right in the browser meaning you don't need to install any software on your computer and meaning that you can use it from anywhere. Best of all, it's completely free and unlimited so you can make as many requests as you like!