A word used in a performing a search.
Keywords are used by Web surfers to describe what they hope to find when performing a Web search. This statement of a real-time want/need has not gone unnoticed by Web marketers, many of whom have tried to benefit from keyword advertising buys and/or search engine optimization.
Google AdWords Keyword Planner – requires signup to Google AdWords. Uses Google’s search query data.
Bing Keyword Research – requires signup to Bing Webmaster Tools. Another source of search query data.
Google Trends – compare keyword popularity over time, across geographies, vs. other terms, more.
SEO Courses – compare at the big list of online courses.