Today, the internet is all-pervasive across our working, social and domestic lives, and it is sometimes hard to remember what the world was like before its introduction and near-universal use.
The internet is the global system of interconnected computer networks that uses the Internet Protocol Suite (TCP/IP) to communicate between networks and devices. It is a “network of networks” that consists of private, public, academic, business, and government networks linked by electronic, wireless, and optical networking technologies.
The internet grew out of research into computer networking carried out by the US Department of Defense during the 1960s, culminating in their first packet-switched system known as ARPANET. During the 1970s and 1980s ARPANET expanded, first across the USA, and then internationally.
In 1990 Tim (now Sir Tim) Berners-Lee, working at CERN, developed WorldWideWeb, the first web browser, and associated tools including, the most relevant to this article, HyperText Markup Language (HTML).
HTML is an example of a Markup Language; a text-encoding system consisting of a set of symbols inserted in a text document to control its structure, formatting, or the relationship between its parts. Markup is often used to control the display of the document or to enrich its content to facilitate automated processing.
In this article we’ll discuss the Markup languages HTML, XML and JSON, and how they relate to the internet.
HTML (HyperText Markup Language)
In the early 1980s, the idea that markup should focus on the structural aspects of a document and leave the visual presentation of that structure to the interpreter led to the creation of Standard Generalised Markup Language (SGML), based on earlier work at IBM. As a document markup language, SGML was originally designed to enable the sharing of machine-readable large-project documents in government, law, and industry.
As mentioned above, HTML was developed in 1990 by Sir Tim Berners-Lee at CERN as part of his WorldWideWeb implementation and he considered it to be an application of SGML. HTML is a markup language that web browsers use to interpret and compose text, images, and other material into visible or audible web pages. Since 1996, the HTML specifications have been maintained, with input from commercial software vendors, by the World Wide Web Consortium (W3C).
HTML markup consists of several key components, including those called tags (and their attributes), character-based data types, character references and entity references. HTML tags most commonly come in pairs like: