There are varieties of file extensions, and the new one with variation pop up each day. For an IT expert, the XML file extension does not seem like anything new. But for a new user of IT XML might be sound like an extension for malware. But it is not a malware; it is one of the widely used file extensions. XML actually means Extensible Markup Language. It means that it is kind of a markup language to interpret and add data to be understandable by humans as well as machines. So XML files are used to interpret, transport, structure and store data. It was designed with the aim of the generality of usage across all over the Internet. Dr. Charles Goldfarb who was involved in the development of XML file system, says that XML is a kind of holy grail for computing because it overcomes the problem of data exchange universally between non-identical systems.
The true history of XML actually goes back to 1970’s when three employees of IBM, Charles Goldfarb, Ed Mosher and Ray Lorie introduced a new technique of forming technical documents, called GML, in which tags were used to structure the data. The name actually consisted of initials of their names Goldfarb, Mosher, and Lorie. Later Goldfarb introduced the term general markup language to reflect the use of the GML better. In 1986 ISO adopted it as SGML (Standard Generalized Markup Language). SGML is not an actual markup language rather it provides a specification for other languages, for example, HTML is used to specify tags for web pages, is an application of SGML.
Although HTML was so much popular from the start but there were many problems which were creating headaches for the web developers especially. There were some loopholes in the presentation which were left open on the discrete of end users, on the contrary, page designers always wanted to solidify their design. The completion between Internet Explorer and Netscape was causing differentiation in the standards and was creating more problems for web developers. These problems and lack of standard were causing the original idea about web pages and usage of web services to drift away because the interpretation of web content was no longer uniform.
Because of these problems, it was widely accepted that HTML is too limited and SGML is too complicated, so there was demand for something much better. In 1990’s a large group of people well known in the industry collaborated and came up with the XML. The collaboration was done using emails and teleconferences. The XML stands for Extensible Markup Language. Basically, it is also the specification for other markup languages. It was developed with the aim of general purpose usability and stability, conciseness, formality and minimum optional features. Its internet application is only one form of its usage. With the introduction of XML now it is easy to specify and store any data, which can be imported and processed by any application using any platform.
There are wide varieties of uses of XML. Some of these uses are as follows.
General application of XML is that it provides a standardized platform to store, access and display data.
While doing web searches and web tasks, XML makes it easier to get desired results because XML defines the kind of data store in the file.
The most popular use of XML is in web development. With XML it is easier to develop an interactive and wide variety with the option to the customer to customize. While data is stored once in XML, which can be used to present to different users with the different style of viewing and processing.
XML use is also getting popular in the storage of data among enterprises. With the use of XML, it is easy to exchange data across different platforms. A business process is getting connected across global scale more than ever. If data hubs are using standardized XML, it will allow business to interact with each other and with customers with ease. Many industries have created systems for storing information in the standardized form using XML for better interaction within the industry. Finance, health care, sciences, and music industry are just to name a few who are using XML for standard data storage. For example in publishing industry XML is used across all document publishers, for example, XML is the basis for Microsoft’s as well as Google’s application as well.
There are two methods to layout data of any XML document. These layouts are DTD (Data Type Definition) and XML schema. DTD is basically an extension of SGML and XML schema is written using XML syntax. There are some limitations in DTD such as it treats all data in a document as a string and does not have the ability to specify specific rules to specific data. For some application, it is not useful that is why XML schema language was introduced.