Keyword research is a practice search engine optimization (SEO) professionals use to find and research alternative search terms that people enter into search engines while looking for a similar subject. Search engine optimization professionals research additional keywords, which they use to achieve better rankings in search engines. Once they find a niche keyword, they expand on it to find similar keywords. Keyword suggestion tools usually aid the process, like the Google Ads Keyword Planner, which offers a thesaurus and alternative keyword suggestions or by looking into Google Suggest.
In a nutshell, Long Tail Pro helps you quickly find keywords in bulk based on a seed keyword that you input. In addition to returning hundreds of related keywords, the tool also shows search volume (monthly search volume), advertiser bid, number of words, rank value, and my favorite Keyword Competitiveness (helps you judge the competition and keyword difficulty).