A domain, also known as a domain name, is the space between the @ in your email address and the.com,.org,.net, and other extensions. (Use yourname@domain.com as an example.) Customers can use domains to find and remember where your company is on the internet. A subdomain is a section of your domain—for example, sales.domain.com or marketing.domain.com—that can be utilised to improve email marketing deliverability.