We start building a website by creating a file named index.html. Here, index.html is a special filename which is presented when the website root address is typed. It means, if many HTML files (.html) are in server and a request is sent by user to the server as the home page URL of the website, then index.html will be fetched initially.
A Basic HTML Page

A tag is like a container for either content or other HTML tags.
IMPORTANT NOTES
- <head> and <body> tags are children of HTML tag.
- HTML is the parent of <head> and <body> tags.
- Most of the HTML elements have opening & closing tag with content in between opening & closing tags.
- Some HTML tags have no content. These are called Empty elements e.g. <br>
- We can either use .htm or .html extension.
- You can use “inspect element” or “view page source” option from Chrome to look into a website’s HTML Code.
Comments in HTML
Comments in HTML are used to mark text which should not be parsed. They can help document the source code.

Case Sensitivity
HTML is a case insensitive language. <H1> and <h1> tags are the same.