Subdomains help divert traffic to specific pages on your website.
URLs have multiple levels to them. These include:
- Root Domain
- Top Level Domain
Subdomains can also be called third-level domains. Depending on how many layers you have to your website, there can also be fourth-level or fifth-level domains.
If adding a blog, store, or any other functions to your website, adding subdomains could help keep them organized. These would keep them separate, while allowing them to all be on your primary site.
Swanky created the above graphic to make it easier to visualize the architecture of a domain.