It is true that even if you attain high rankings search engine, you may not get the appropriate traffic you always wanted, and it happens if you select the wrong or repeated keywords. For any marketing strategy success, it is very difficult to know its audience and means to reach them. It is essential to take care while researching the new keywords about the location, country and the region. Focusing on region would help to get targeted viewers and it is done through a technique of local marketing in SEO but as we are discussing some other topic over here, we cannot afford to have least traffic on our site because of some older keywords. Keyword research needs intense dedication and consumption of time but if done in the correct way, it will come out with bulk traffic on your website with a nonstop course. Using the best and fresh keywords to portray your site helps you to get those people on your website who can also be your client in future times. 

In present times the search engines never compromise on the quality of the content and expect to get a unique one every time. So, they only locate those web pages which are having genuine content.
There are different kinds of keywords which are used for different SEO purposes
Primary Keywords
A primary keyword is the keyword or a keyword-phrase that we use before all other keywords. It's the most important element in the SEO and the entire content of the web page depend on these keywords to be sourced on the Home Page of the website.
It must come within the Home Page's content. And it will be very good if it comes primarily on the first paragraph of the written content. This is very important to the SEO point of view because search engines consider the first words of the content as the important one.
When a search engine indexes a web page, the first words that tell the search engine about what the web page is about and what search engine queries respond to that web page content.
A web page should take care of topic that if the website is describing about a service then it should only have keywords related to that only never with the owners name or the location etc.

Secondary Keywords
A secondary keyword is that keyword which is used after the primary keyword or keyword-phrase and it immediately go after the primary keyword which is already mentioned in the important lists of keywords.
Secondary keywords aren't required much but whenever they are set in into your web page, they boost the chance of drawing website traffic that uses the subsequent top keywords to search them.

Tertiary Keywords

Tertiary keywords are a group of keywords or keyword-phrases usually which are not more than ten words and are used after the secondary keywords. These are also capable to raise the chance of attaining bulk website visitors who use different keywords to search.
These keywords are set up in such a manner behind the secondary keywords in a website’s description through metatags, and also, all through the page's content.
Therefore, it is noteworthy that new keyword researching for Search Engine Optimization can create miracles for your online traffic.