How does site registration in SE's and Directories influence link popularuty?

[amateur]

Hi all!
I know that link-exchange rise page-rank of the site. I know that registration in catalogues and search engines also necessary for site promotion. I just can't understand exactly - if my site listed in a search engine or a catalogue may it be treated as link to my site or not. I heared that if site listed in catalogue it is treated like a link and rise my page-rank, and if in a search engine - it doesn't influence on my page-rank, because my site is just indexed and become only searchable.
Would somebody clear this matter to me? I would appreciate it, excuse me for such a simple questions - I am just an amateur in this sphere :)

[searchenginemarketing4u]

ANY website that links to your site is a proper link, but it may not do you any good as the page need a good-ish page rank to show up in Google and count towards your inbound links.

Try going to Google and typing in your keyphrases and see which companies come out on top. Then type: link:www.companydomain.com to see where your competitors are getting their links from. Visit these sites and request links from webmasters.

[amateur]

Thanks for quick reply.
I really know about exchanging of links with well-rated sites. I just want to understand - if I get listed in a catalogue or serach engine is it link on my site or not?