Commonly known as "HyperText Markup Language". This is the computer language used to design websites. After the invention of computer later in 1980, a physicist worked on something which led the basics of HTML. There are many same versions of HTML. And now a days mostly and commonly used version is 'HTML5'. In HTML5 there are new tags for designing purpose so they helped programmers to design some good stuff. Web pages does not show coding of HTML and show some good design instead. So HTML can be said the building block for websites. HTML works with css (Cascade Styling Sheet) to design web pages.