It is hard to say, many a times I think web services=web application, it is an application/service that is accessed via web over a network such as the Internet or an intranet. SOA and web services are two different things, but web services are the preferred standards-based way to realize SOA.
SOA is an architectural style for building software applications that use services available in a network such as the web. It promotes loose coupling between software components so that they can be reused. Web Applications in SOA are built based on services. A service is an implementation of a well-defined business functionality, and such services can then be consumed by clients in different applications or business processes.
