Since the list of currency exchange rates that we want to download from the Internet is provided as an XML file, it's a good idea if we have an understanding of just what an XML file is in general terms.
So let's take a step back and first answer the question, for what is XML an abbreviation? XML is an abbreviation for eXtensible Markup Language. As its name implies, XML is an evolution of something even simpler known as a Markup Language.
Essentially a Markup Language allows us to embed tags, using whatever syntax is used by the language, into a document and have those tags interpreted as formatting rather than content. A good example is bold text or a font. Somehow within our document we need to indicate that some text is in bold face or that some text is in a different font. We need to indicate both the attribute type and its span.
Markup Languages have been used on computers since the days of mainframes. Apps like Microsoft Word or Word Perfect originally had their...