Web services are applications stored on web servers that you can access remotely through standard web protocols (HTTP, SOAP) and data formats (HTML, XML...), whatever the systems and programming languages.
Web services comprise a set of operations, each of which contains a SQL query for retrieving data from a database. If you use web services to query databases, you no longer need drivers to communicate with those databases. The following example shows the result of an HTTP request for a database web service: