What is the purpose of keyword in SEO?

[rajaram]

What is the purpose of keyword in SEO?

[Hostfinch]

Keywords are the most important SEO element for every search engine, they are what search strings are matched against. ... Keyword is a single word, and while a combination of those keywords makes phrases. These keywords or phrases are used by the search engines to populate the subjects over the internet.

[deepak-sh]

Keywords are the most important factor in SEO. You can find keywords by using Google adwords keyword planner and Google Trends.