what is a gateway?

I've tried searching for the meaning of gateway in google but i'm having a hard time understanding it. What is the diff between gateway and DNS?Can someon pls give me an elementary meaning and diff between gateway and DNS? pleasse? Is it also possible to ping a gateway?

Definition: Drum roll please... A network gateway it's a system that joins two networks together. There is also a company known as Gateway Computers... theres is a few other meanings but I just posted up the one I thought you would wanted to hear.

Domain Name Service, it's a Internet service that translates domain names into IP addresses. The www is really based on IP addresses and when you use a domain name a DNS service has to translate the name into the an IP address. For example, the domain name www.AntiOnline.com would translate to a IP like 63.146.10X.XXX or blah blah.