How can i use an image as a link

Answer 1

If you mean that you want to be able to host your images online and then use it's url, then follow~ swim ~'s answer.

If you mean that you want to turn an image into a link so that when you click it, you are redirected to that url, then just enclose it in an anchor tag
<a href="url"><img src="link-to-the-image"></a>