i am newbie in web. now i developing an blog site. I am using google adword tool for keyword selection. But the traffic estimation between Broad Search, Exact Search and Phrase Search is huge. Would you please tell the difference between Broad Search, Exact Search,Phrase Search match. However i understand little bit by reading from some website. But most important question is Which keyword estimation should i use for my content optimization that helps me to rank in search engine. Any response is appreciated. Thanks