Welcome
Hyper Text Mark-up Language, commonly known as HTML is basically, a communication interface between the computer world and the human world. It is a programming language used to specify or describe the composition or structure of information in the form of text in a document in order to supplement the text with objects such embedded images, interactive forms etc. 
HTML specifies the text based information found in a document by denoting and breaking it down the text as headings, links, lists, paragraphs etc. The main aim of HTML is to design an electronic version of a webpage, which the computer will then be able to present the information in a retrievable way to the human world across the internet by use of browser programs of the World Wide Web.
When one wants to program in this text Mark up language (HMTL), they use programming tags, which are surrounded by angle brackets (). The brackets are the meta information communicating and explaining to the computer what the content embraced is. HTML puts more emphasis on structure to make the files more useable, rather than the appearance of the files. However, to some degree, HTML can describe the semantics of a particular document thus can include an embedded scripting language code as the JavaScript, which has an effect to the behaviour of web browsers.
Fundamentally, when you open an address of any website (URL) on the internet, the first part of the address is always marked HTTP (Hypertext transfer protocol) which signifies that that document you are accessing is written in the Hyper Text Mark-up language.