<video>

tag should contain

controls

attribute in order the video player to have controls on the screen

<video>this text</video>

will appear on the screen if the browser is not able to display the video in a certain format or if the video fails for any other reason. Example:

<iframe>Sorry error occured</iframe>

Absolute URL example:

https://google.com

Relative URL example:

/page2.html

<header>

- defines a header for a document or section;

<nav>

- defines a set of navigation links;

<main>

- specifies the main content of a document;

<footer>

- defines a footer for a document or section;

<article>

- defines an article;

<section>

- defines a section in a document;

<aside>

- defines content aside from the page content;

<small>

tag makes text inside it a little bit smaller

<big>

tag makes text inside it a little bit bigger

<br>

and

<hr>

tags are called single tags or empty elements

Default title will be the name of the html page if it's untitled (meaning if the title is not provided)