HTML: What's the correct form of BR?

Question

How is correct to write the br tag in html?

or

or anyt

Answer 1

<br/>.  

Here:

Some of the most common errors in the usage of XHTML are:
Not closing empty elements (elements without closing tags in HTML4)
Incorrect: <br>
Correct: <br />
Note that any of these is acceptable in XHTML: <br></br>, <br/>, and <br />. Older HTML-only browsers interpreting it as HTML will generally accept <br> and <br />.

Answer 2

You should use <br /> because it respect the standards XHTML, HTML and in general (XML). Because every xml tag needs to close.