why we use comment in html

Answer 1

<!-- This is an html comment -->

Comments are used to leave notes in your code to understand it more easily, or to dummy out blocks of code you want to be able to put back easily.

Answer 2

<!....comment....>

Answer 3

Comments make code and syntax easier for humans to read and understand what the code is doing.

Answer 4

When you are building a program these are notes for the developers and anyone else who is reading your code to make use of it. Or it could be just a reminder to yourself about why you did something. You might leave notes about requirements to edit the code to make it work best or which file to edit instead or cautions about editing or which version/edition it is and author credits and program webite --- so many reasons!