<P> HTML elements are the building blocks of HTML pages . With HTML constructs, images and other objects such as interactive forms may be embedded into the rendered page . HTML provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links, quotes and other items . HTML elements are delineated by tags, written using angle brackets . Tags such as <img /> and <input /> directly introduce content into the page . Other tags such as <p> surround and provide information about document text and may include other tags as sub-elements . Browsers do not display the HTML tags, but use them to interpret the content of the page . </P> <P> HTML can embed programs written in a scripting language such as JavaScript, which affects the behavior and content of web pages . Inclusion of CSS defines the look and layout of content . The World Wide Web Consortium (W3C), maintainer of both the HTML and the CSS standards, has encouraged the use of CSS over explicit presentational HTML since 1997 . </P> <P> In 1980, physicist Tim Berners - Lee, a contractor at CERN, proposed and prototyped ENQUIRE, a system for CERN researchers to use and share documents . In 1989, Berners - Lee wrote a memo proposing an Internet - based hypertext system . Berners - Lee specified HTML and wrote the browser and server software in late 1990 . That year, Berners - Lee and CERN data systems engineer Robert Cailliau collaborated on a joint request for funding, but the project was not formally adopted by CERN . In his personal notes from 1990 he listed "some of the many areas in which hypertext is used" and put an encyclopedia first . </P> <P> The first publicly available description of HTML was a document called "HTML Tags", first mentioned on the Internet by Tim Berners - Lee in late 1991 . It describes 18 elements comprising the initial, relatively simple design of HTML . Except for the hyperlink tag, these were strongly influenced by SGMLguid, an in - house Standard Generalized Markup Language (SGML) - based documentation format at CERN . Eleven of these elements still exist in HTML 4 . </P>

Who developed hypertext markup language (html) in 1990 at cern