I want to know more details about the Keyphrases. How it is usefull for SEO and give me the some hints or example for keyphrases. My site is still fairly new, please help me anybody else....
I want to know more details about the ... well, dogs. Give me some hints or examples for the dogs. Buddy, your question is WAY too general. You need to fill the gaps in your basic knowledge first (open the first link in my signature, for instance), then ask some more specific question.
A phrase is a group of words functioning as a single unit in the syntax of a sentence. For example, "I post useless threads" A word is the smallest free form in a language. For example, "useless". I hope this helped.
Use a free tool such as google keyword tool. Put in a keyword you are interested in and see all the phrases or variations that pop up. The data that is given will give you an idea what people are actually searching for and then you can decide what keyword phrases are worth marketing or getting backlinks for. So if you are in the dog niche for an example are you selling a service a product or both? It is good when starting out to focus on a dozen keywords or so then branch. It is very important to have that initial focus until you get some reasonable traffic.