why domain registration isn't free?

[manish manish sharma]

[tazz]

Because it's not only about registering a "name". First, "someone" has to make sure there are no 2 identical names. Who would do that for free? Nobody (that's why you pay). Second, your domain name has to point somewhere (to an IP in this case). How do you do that yourself? You don't. There are also many other features like creating email addresses @yourdomain.com, redirects) and many other things that you don't need to worry about as a customer. That's why you have to pay for a domain. If you want free domains, there are plenty. As expected, a free domain is not as good as a payed domain.
Good luck!

[Dennis]

Because people would hoard website domains. And btw, you're only renting these domain names