HTML (Hyper Text Markup Language) is a language that makes the documents of the website readable to human which we normally see while browsing the web. It was created by Tim Berners-Lee in 1989. We don’t know the exact date of HTML creation, since it was a long term project, but the birthdate of the first HTML website is known to be on August 6, 1991. The first publicly available description of HTML was a document called "HTML Tags", first mentioned on the Internet by non other than Tim Berners-Lee.
Every webpage may actually be a HTML file. Each HTML file is just a plain-text file, but with a .html file extension instead of .txt, and is made up of many HTML tags as well as the content for a web page. A website may often contain many html files that link to each other. HTML files can be edited with any kind of text editor since it is just a text file.
HTML tags are the hidden keywords within a web page that define how your web browser must format and display the content.
Mostly tags have two parts, an opening and a closing part. For example, is the opening tag and is the closing tag. The closing tag contains the same text as the opening tag, but has an additional forward-slash ( / ) character in front of the word.
CSS is short for Cascading Style Sheets It is the preferred way for setting the look and feel of a website.It define the colour, size and position of text and other HTML tags, while the HTML files define the content and how it is organized. Separating them allows you to change the colour scheme without having to rewrite your entire website.Since it's cascading, setting the colour of body text will mean all headings and paragraphs within the body will also be the same colour.
World's first HTML site is still running, wanna check it out? World's First HTML Website