Subdomains are basically a subset of the main domain.
If we take seo.mikgroup.ch,
Then “.ch” is a ccTLD or Country-Code Top-Level Domain,
“mikgroup.ch” is a second-level-domain and
“seo.mikgroup.ch” becomes a third-level domain.
Webmasters occasionally refer to third-level domains as subdomains.
Short keywords used in a subdomain can impact rankings, but make sure you don’t stuff it.
Subdomains are created to simplify the website’s layout structure. It becomes really easy to manage your website by using subdomains.
When used properly, subdomains can help organize the entire website, which will create a more user-friendly and easy-to-navigate website.
Another factor that will help your overall SEO strategy is to establish your site as an authority in your niche. Using subdomains can help you achieve this.
Typically, subdomains are viewed as separate entities so that each subdomain can rank on its own.
Is your site focused on local areas? Increase your local optimization by creating local specific and geography targeted subdomains.