dns is just like this,
DNS- is domain naming system-it maps the ip address of a domain or computer offering services to either private or public,
you use DNS so that you wont memorize the whole ip address of a certain service provider say, 209.131.36.158 or yahoo.com
this (dns) offers a great idea in to an extent that we will only memorize the ALias of an address, that in turn will make make it easy for sus to recall.
there are some cases that your boss will talk about forward look up zone and backward look up zone, these two are the basis of dns server, In my own understanding
just like when you want to know the ip address of a certain website, for example
ping
Yahoo!
you will get
reply from 209.131.36.158:bytes=32 time =213 ms TTL=51
reply from 209.131.36.158:bytes=32 time =192ms TTL=51
reply from 209.131.36.158:bytes=32 time =239 ms TTL=51
reply from 209.131.36.158:bytes=32 time =195 ms TTL=51
now if you can remember the ip address and you cant memorize words,
you can place this address to the address bar of your browser
say
209.131.36.158= then yahoo.com will come up,