why <br/> tag has no end tag?

Answer 1

<br> (correct HTML5) and similar tags like <hr> are called 'void elements'. Apparently, they don't need a closing tag because they don't have any content. If there was content like in <h1>A Heading</h1> the closing tag is needed to tell browsers and screenreaders (for blind people) the heading ends right here after 'Heading'.

Answer 2

does that mean its a single action rather than content?

Answer 3

because it is void tag and not require closing tag

Answer 4

because it's unary tag