In a nutshell, a web service is a method that can be called by a client to perform a particular task and return some results. Such results can be in plain text, as links, or media that can be interpreted by browsers. What makes it different from any regular method is that this method is a cross platform, which means you can call it from practically anywhere and get the output in a convenient and native format. For example, you spend countless hours to develop an algorithm on C# that performs a certain task. Your boss is happy, and she/he asks you to deploy it on your Unix database server. However, there is a slight problem here. C# code uses the Microsoft .NET Framework that happens to run only on the Microsoft Windows operating system; therefore, it is a challenging task to port this algorithm to Unix. One solution will be to rewrite the algorithm to run on Unix, which will lead to two versions of the code scattered on multiple locations. However, this will introduce...