The concept of Service Oriented Architecture is not entirely new. SOA essentially promotes the separation of the service interface and the execution environment. SOA also promotes the alignment of IT infrastructure to meet the business service requirements. Although SOA can be implemented in a number of ways, utilizing web services provides several advantages, particularly because web services bring enterprise application closer to business automation. Two of the most popular technologies for implementing SOA through web services are Microsoft's .NET and Sun Microsystem's Java Platform, Enterprise Edition.
In the next part, we devote our attention toward the building blocks of SOA technology. Three elements included here are the derivatives of the extensible markup language, namely SOAP, WSDL, and UDDI, and business process-related XML vocabularies such as BPEL and CDL. Advanced elements of web services address aspects such as security, reliability, quality of services, and so on.