Web services technology provides operations, also known as methods in the context of client applications. Using the vSphere Web Services SDK and your choice of programming language, you can create client applications that invoke these operations to perform the full range of server-side management and monitoring tasks.

The Web services API is defined in Web Services Description Language (WSDL) files. The WSDL files are used by client-side Web-services utilities to create proxy code (stubs) that client applications use to interact with the server.

Client applications invoke operations by calling proxy interface methods. The client proxy encodes an operation invocation into a SOAP message and sends it to the server. Simple Object Access Protocol (SOAP) is a programming-language neutral XML format. SOAP message translation is transparent to the developer.

Communications between client and server occur over HTTP or HTTPS. HTTPS is a secure form of HTTP that uses SSL to encrypt client-server communications. The default is HTTPS, but you can configure the VMware vSphere Web server to support HTTP. (See Endpoint Configuration for HTTP.)