Google PageRank and Alexa Rank

Hi, I am new to SEO and evreything, and I just had a quick question, what does Google Page rank and Alexa Rank actually do? I mean I know it rates how many back links you have, but for example will a PR5 site outrank a PR4 site on google search? Thanks.

I would not rely on PR and even less on Alexa Rank.
PR "should" rate how many backlinks your site has and how important they are, but in 2013 that doesn't really matter.
I mean you can buy 100k backlinks for your a few days ago established blog but Google will give a f... on it because they will recognize it.
Everything around Alexa is c rap, they rely on their toolbar and only a few permill have installed it, so it isn't very representative.

Alexa page rank is basically a very inaccurate metrics will little or no value - zero credibility

G PR Circa 2006 - 2007 had some value then G slapped selling PR links and since that it has never recovered presence and/or metrics respect

Hope you could Google is simply. Both are important but in some specific niche. Found a better resource for you here :
http://bloggingzene.com/alexa-rank-vs-google-page-rank/

well Page Rank and Search Engine Ranking Position is very well explained by GreyWolf in this thread: http://www.blackhatworld.com/blackh...s-about-google-page-ranking-serp-ranking.html
as you will see by yourself , PR and SERP of a site are not related that much, but i will not go into further details since you can read it by yourself at the thread.

at the other hand, Alexa ranking have nothing to do with your keyword ranking. it is related based on wold daily visitors, and if you ask me it is C rap since it gives no details about niche or targeted visitors. imagine 1000k visitors at your site, which are searching about flowers, but you sell Laptops. okay you will have a nice alexa ranking, but 0 sales.
maybe the example i took is not the best, but if u ask me, you need targeted visitors, or no visitors at all.

hope it helped. Good Luck.
Leobar

alexa and google pr doesn't matter, google pr only matter when you are trying to get a link from high pr resource, then it would help.

Alexa rank tells you that how much traffic is coming on your site. On the contrary page rank has nothing to do with traffic. It it a quality measure by google. Relevancy dominate both of these for search engine ranking.

searchengine placement does not depend on PR!

Alexa rank is for traffic estimation while
Page rank tells overall strength of your web page, can be valuable when you are going to sell your domain name or you are going to buy or sell links.

page rank is an algorithm of the Google where it decides page rank of the site according to site popularity and visitors.

Google can easily count your backlink because Google have their crawler which moves regularly on the different sites and these crawl you links and save in their database. when next time they will get your link again they add your link to their database.