According to Google, subdomains and subdirectories are seen as equal when it comes to indexing and ranking. That said, real-world case studies show that subdirectories tend to rank faster and more effectively than subdomains on the first page of the search engine results page (SERPs).

A subdomain is a prefix added to a domain name to separate a section of your website. Site owners primarily use subdomains to manage extensive sections that require their own content hierarchy, such as online stores, blogs, job boards or support platforms. Subdomains function as a separate website from its domain.

Subdomains are the third level of a domain's hierarchy and are parts of a larger top-level domain. They are added in front of the root domain and separated from the domain name with a period. For example, "blog.example.com" and "english.example.com" are both subdomains of the "example.com" root domain.

While subdomains can work well for some companies, depending on their goals, a subdirectory is often a better choice for SEO.