DOCTYPE tag
<!DOCTYPE> is a declaration tag which is the first thing in your HTML file. It does not represent any HTML tag but the version of HTML the page is written in. Its Syntax representation is
<!DOCTYPE>
Note : <!DOCTYPE> tag does not have case sensitive issue so one can write in uppercase as well as lowercase
<!DOCTYPE> tag explanation
Page Title h1 tag represents the most ideal heading.
My first paragraph.
Tip : All modern browser support <!DOCTYPE> tag. This tag helps browser to render HTML easily.