It refers to a phrase or a word that refers to a specific mindset that desirable prospects look for. The brand related keywords are important than the small and indistinct keywords as they generally emerge at a later stage in the buying cycle.
It is a conventional measure of search engine importance that implies how many important keywords were included in the content of a website's page. But, keyword density is not a relevant measure of importance in a broad criterion of open search index now.
Keyword Research Tools
They include tools that help you in finding prospective keywords through past search volumes, bid prices, search trends and page content from associated websites. The most reputed keyword research tools are:
SEO Book keyword research tool