You need to tailor your resume to the job opening: identify the keywords in the job description and make sure to refer to them in your resume. (uptowork.com)
If you are unsure, there are handy tools to help identify the keywords you should focus on. (careercloud.com)
In other words, it is a natural and business - specific way of identifying keywords without the help or qualification of external information. (remonline.com)