The domain is an identifier of a web page on the Internet. Firms and companies can be found on the Internet by their domain names.
The top-level domain (TLD) is the part of the domain name that is at the end after the period (for example, https://www.webtrustcr.com ). There are different top level domains .com, .org, .biz, .net, etc.
DNS or Domain Name System is a hierarchically organized system of databases responsible for mapping domain names to corresponding IP addresses. Knowing this helps you put your domain online.
When the domain expires, its owner has about a month to get it back. In case no steps are taken to return the domain, it will be lost. The domain owner receives the corresponding email notifications.