All the tags are called elements of HTML. An element has start tag and closing tag.
<Start_Tag_Name> Write some text here... </End_Tag_Name> <h1> Write some text here... </h1> <p> Write some text here... </p>
Some elements have not end_tag_name called empty element, e.g. <br>.
<br> tag is for break the line.
You have a long paragraph and you want to break the line and start from new line you can use <br> tag.
<p>I am paragraph text and <br> break the line. Can you see the difference </p>