Domain names are part of the structure of the Internet. A web user types in the domain name into their browser and they see the website that relates to that domain name.
The way it works is as follows...
Domain Names point to a Name Server.
The Name Server point to the DNS server which holds the IP address of the Website.
The Browser then goes to that IP Address where the web server will display the website.
With Sellr, we use the Cloudflare system. This is a fantastic system which will both protect your website from malicious attacks, it is also a CDN (Content Delivery Network). A CDN caches parts of your site in local caches around the world, so it will make it fast loading for website visitors all around the world. Cloudflare is also free to use. (There are upgrades available but you do not need to use them with Sellr).