The domain concept was created with the aim of facilitating the memorization of computer addresses on the Internet.
Imagine having to memorize a number like 192.168.200.203 (IP address) and insert it in the navigation bar to be able to consult the DNS site and then decorate several other sequences of numbers of sites that you use regularly.
It would be a very difficult task and the Web certainly would not have the success it has today. Writing registar.co.mz or google.co.mz is quite intuitive and easy to remember.