Cloud

Cloud computing is evolving as a strategic platform for sharing resources such as

Traditional advantages of cloud services include

Service models

IaaS = Networking + Storage + Servers + Virtualization

Paas = IaaS + O/S + Middleware

SaaS = PaaS + Runime + data + Applications

Examples:

IaaS: DigitalOcean, Linode, Rackspace, Amazon Web Services (AWS), Cisco Metapod, Microsoft Azure, Google Compute Engine (GCE)
PaaS: AWS Elastic Beanstalk, Windows Azure, Heroku, Force.com, Google App Engine, Apache Stratos, OpenShift
SaaS: Google Apps, Dropbox, Salesforce, Cisco WebEx, Concur, GoToMeeting

Apparently, there is also BaaS or mBaas: (mobile) Backend as a Service.