what is the fuction of '#'?

Question

What is the fuction of # ?

<nav>
<ul>
<li><a href="#">Home</a></li>
<li><a href="#">Services</a></li>
<li><a href="#">About us</a></li>
</ul>
</nav>

Answer 1

It is a minimal relative link to actual page...

If your page url is: http://mydomain.ext/index.html, so the absolute link of your <a>s tag is: http://mydomain.ext/index.html# wich is the format of an url to refer to a particular id in the page ( to auto-scroll to ). Setting with nothing folling, is a hack to use <a> link elements click event without reloading the page ^^

Answer 2

this means that the same side is the target.
similar to a refresh