URL is one of the important elements of SEO and affects your Page Rank.

How important are URLs in SEO?
Importance of URLs from the SEO point of view is highly controversial question. In the hundreds of search engine algorithms is it an important one to be looked by the search engines? According to some SEO experts, placing keywords in the URL is vital for your website but highlighting your brand name in the URL is equally important. On the other side some SEO gurus never support keyword rich URLS while indexed by the search engines.
What exactly constitutes a search engine friendly URL?
There should be bit relevance between the URL text and the content on the corresponding webpage. This level of relevance between the URL text and the content on the corresponding webpage determines the page success on the search engine algorithm level. Relevant URLs seems informative to the web browsers and search engine spiders also supported by the search engine spiders. Targeting keywords in the web URL is a great idea to get higher ranking in the search engine results.
Keyword oriented Vs Brand Promoting URL

Does your URL should be keyword rich or it should be promoting your brand is a million dollar question. If you are using a keyword oriented URL it is definitely going to boost up your website at SEO level but it will be unable to promote your brand identity in the market. So what should be the best idea? A search engine friendly URL or a URL reflecting your brand name?

Your URL is the first step of your online presence used for you branding in the market. The URL should be catchy and appealing for the web users but it should be search engine friendly as well and it will be another advantage. While crawling the web pages search engine spiders also consider pages having the search term in the URL. So, search engine friendly or keyword rich URL will definitely be going to boost up your online business by ranking you top on the search engines.

All the major search engines do support the indexing of keyword rich URLs. Portion of the URL matching to the search query is always displayed in bold in the Google and Yahoo search engine results. Top 20 URLs is the search engine results are which contain the search string.

Some characteristics of the successful URLs are as follows:
Ideal URLs are short and simple. Shorter is always better. Short web addresses are always top on the popularity charts as they are easy to remember so the typing mistakes are least possible with short URLS.
A successful URL should be the descriptive one. The URLs should be a preview of your products and services.
A URL easy to remember always performs better as compared to the complicated one.
A successful URL requires a bit creativity to combine with the unique feature of simplicity and descriptiveness to display it in the first encounter. For example, a URL after your name or your firm's name, may not-in the long run-be the best choice.