how is use Cloud computing major serch engine Like Google Yahoo etc

[myindiahub]

Hey
i have listen about Cloud computing but not properly know about it that what is its main concept and how its work in internet. and i know that all major search engine and email provider use this cloud computing technoly.
please suggest for it

[Nile Hadwards]

Reliability improves through the use of multiple redundant sites, which makes cloud computing suitable for business continuity and disaster recovery.Nonetheless, many major cloud computing services have suffered outages, and IT and business managers can at times do little when they are affected.

[John23]

Metering cloud computing resources usage should be measurable and should be metered per client and application on daily, weekly, monthly, and annual basis. This will enable clients on choosing the vendor cloud on cost and reliability (QoS).

[lingoway]

is there any use of cloud computing in SEO?