HTML uses code example

Example 1: what does html represent

HYPER-TEXT MARKUP LANGUAGE
It is one of the standardised markup languages that 
defines the layout of a webpage.

You can use CSS to aid in the styling of the webpage.

Example 2: what should i use for html

You can both use notepad(Pc), TextEdit(Mac) but thats not really good
so i would probably use atom, sublime text or visual studio code

Example 3: what is html used for

html is used to make web pages and it discribes the layout of a web page

Example 4: HTML

p
<p>
hello world
</p>