SaaS is a model of software services provided through
internet. Through such model, software services providers
integrates the application software together on their cloud
servers. End-users purchase the software services on internet
based on their needs. The providers charge their service fees
to customers, based on the users’ specific orders and
requirements such as software kinds, numbers, technical
supports, service durations, etc. Through an internet browser
to deliver software supports. These kinds of business model
can be found in Salesforce.com (for sales force applications),
Oracle/Siebel (CRM applications), Workday (for ERP
applications), and Citrix (various applications).