'backlink' is just one of the terms used to describe links to your website. Also incoming link, external links, etc...

to increase the number of links to your website, you should...
- submit free content/articles to authority websites and receive a backlink in return
- submit your website to as many directories as you can find which are relevant to your site
- share links with similar websites (not worth much in my opinion, unless there are many links and sites don't link directly to each other)

But remember, quality - not quantity - is the most important factor with links, so the more 'genuine' and 'relevant' it seems, the more weight it will carry towards your website.

Hope that helps...