Some important HTML tags which will be helpful for beginners.

<.....> </......> all tags will be like that.

!DOCTYPE ......it defines documentation.
html tag.......it defines html documentation.
head tag.......it defines information related to documentation.
title tag........ it defines title of HTML web page.
body tag.......it defines the main part of html output of web page.
h1 h2 h3 h4 h5 h6 tags...... it defines headings of html part.
p tag.......it defines paragraph of html
br tag....... it defines single line break or end line.