Domain is the first step towards launching your website, without a domain, your website will not be recognized, in India, the mostly used TLD (top level domain) are .com, .in and .co.in. We also have options to register .net.in and .org.in, but these are not so popular domains.
The purpose of a domain name is, it provides an easy to remember name for your web server, it is easy to remember google.com than its ip address which is 188.8.131.52. All major brands have there domain registered in order to protect there goodwill, a domain name is considered as an intangible intellectual property.
Karni Infotech can also register domains for universities and educational institutes, we can register .ac.in, .edu.in domains for your institute.
Domain names are renewed on a yearly basis, you can register your domain for 1 year or maximum upto 10 years, every domain is a unique name consisting of 255 charecters, once registered, it cannot be used or registered by someone else, unless it is not renewed.
The domain is considered as expired once its not renewed, and its deleted from Public Domain Registry within 60-90 days, that means, once a domain gets expired, it can be registered by anyone after 90 days, there are many domain registrars (like Godaddy), who sell expired domain names once the domain is not renewed.