How can I set DNS for my website

I have developed a website using LAMP. Right now we are accessing the website using ip address(in intranet) ie http://10.192.192.162/IntraWeb/index.php

I would like to access the web using name instead of ip address.
ie
http://www.projects.org/IntraWeb/index.php

How can I set DNS for accessing website in the intranet using name ie http://www.projects.org/ instead of ip address
How can I set DNS for accessing website in the internet using name ie http://www.projects.org/ instead of ip address

Thanks in advance

You can : 1. ask your DNS admin to set proper DNS records, i.e. reverse, cname, A records, etc, having in mind that you use the normal name servers on your machine.
2. Ask your colleagues around you to add :
"10.192.192.162 projects.org" in their /etc/hosts file, or the respective hosts file on windows :