How does search engines treats sub-domains?

[stcole]

How does search engines treats sub-domains? Are they going to effect the SEO of one another. Or the root domain SEO will effect the SEO's of sub-domains?

[Paul]

The root domain have some effect in the sub-domains but the sub-domains have no effect on the other sub-domains. They are considered totally as different sites unless they are penalized. For example google itself has many sub-domains but they are considered as separate sites such google adwords, analytics, adsense, gmail etc.

[ChetanModi]

Never heard about it, thanks for shared and getting knowledge from it.

[sulbha]

hi,
Simply put, a sub domain is part of a main website. However, unlike with a subfolder or subdirectory, it is considered as a separate domain by search engines.

[Sudeepkhana]

Web search tools consider a subdomain as a different substance. In spite of the fact that there is some relationship between the principle space and its subdomain, it is most likely to your greatest advantage to go ahead with a subdirectory structure unless you have a considerable measure of substance.