Keywords are the words that web surfers enter in search engines to find web sites. It is important that your web site has good search engine rankings for popular keywords that are related to the theme of your web site. In this  manual, we use the term "keywords" for single word keywords and for keyword phrases, for example "hiking boots shop New Delhi".

The right keywords are important to the success of your SEO activities!
It's pointless to optimize your web pages for keywords that nobody uses in the search engines. In addition, in order to get targeted visitors, the keywords must not be too broad or too general. Good Keyword Generator tool helps you to build a list of keywords that people use on search engines to find your web site.
Which keywords are the right keywords for your web site?
Use focused and targeted keyword phrases that are common enough so the web searcher will use them, but selective enough that they don't return millions of matches. Very specific keywords generate highly qualified, targeted traffic that increases your sales. The first step in choosing the right keywords is to make them very specific.

• use keyword phrases that consist of two to four words
• avoid very competitive keywords
• be specific
• only check the keywords that are important to you

For a successful online marketing campaign, you have to target the right keywords.

The keywords you use should be relevant for your web site and web surfers should be searching for your keywords. Most people use a two to four word phrase in a search, so phrases are very effective. Single words cannot be promoted effectively. For example, it is not likely that someone looking for "free software download" is going to type just "software" into the search box. Avoid the most popular keyword phrases because you'll be competing with millions of other pages for a search engine's attention. It is unrealistic to think that a new web site could rank number one on a popular phrase like "mp3". More established companies who have been on the Internet for several years will have the big advantage of a high link popularity.
Internet users who use four-word searches are more likely to purchase goods or services than those using fewer words (source: Oneupweb Research).

Start with multiple word keywords and then extend your keyword list.
Search engines analyze all pages of your web site and put them in a context. Start with multiple word keywords and then extend your keyword list. If you're selling MP3 files, you should optimize your web pages for keywords such as "independent bands mp3", "alternative grunge mp3", "pop music mp3 download" and similar keywords first.
If your web site many rankings for these keywords, search engines will find out that your web site is relevant to the mp3 topic. As soon as search engines consider your web site relevant to this topic, it will be much easier to get high rankings for keywords such as "mp3 download" or even "mp3".