at's the difference between SOA and web services?

What's the difference between SOA and web services?

SOA Service Oriented Architecture is the overarching strategy for building software applications inside a company—think of an architectural blueprint—except that in this case, the architecture calls for all the pieces of software to be built using a particular software development methodology, known as service-oriented programming.

Web services, meanwhile, are a set of standard communication mechanisms built upon the World Wide Web. Web services are a linking and communications methodology. SOA is an overall IT strategy.

Source: http://www.cio.com