Databases aren't the only place you can find massive amounts of information. All kinds of specialized software programs store vast quantities of data in their own way. More often than not, when you need to get information out of (or into) one of these programs, you'll use XML.
XML is an all-purpose system for structuring and organizing data in a file. XML lets you exchange information with just about anyone, and send your spreadsheet data to other businesses that don't use Excel, or analyze raw information created with other programs.
For example, instead of saving data in Word documents, Excel spreadsheets, or ordinary text files, you can save data in an XML file. XML alone sounds pretty modest, but this simplicity is deceiving. Two factors make XML really special:
XML is flexible. You can tailor XML to store pretty much any type of information: pictures, product catalogs, invoice data, receipts, catalog listings, the maintenance specs for every Dodge Minivan ever built, and on and on.
XML is widespread. Computer programs written in different programming languages (Java, Visual Basic, C++, and so on), or running on different operating systems and computer hardware (Windows, Mac, Linux, and so on), can all use XML in exactly the same way. XML is a perfect solution for exchanging information between people, companies, and even computers programmed to send data to one another automatically. (Features like this last one cause supply-chain management types to start drooling ...