A domain, or domain name, is essentially a web URL or address. You’ll see the domain name after the http:// or www in a URL.... Simply put, your domain is the digital equivalent of a store’s physical address, and is how your customers find and access your online business.
Add a custom domain name to your Shopify store to give your website a name that’s easy for new customers to remember, and to create a consistent online presence, however your business grows. Custom domain names, such as website addresses with .com at the end, help new customers know where to find you online, and help new ones to discover you online through search engines like Google.
With Shopify's domain registration, hosting, and easy domain management, your domain names, website builder, store, and sales are all in one place, instead of having multiple domain names across multiple sites.