In many cases, your resume is the first document a hiring manager will look at when reviewing your application, and therefore is a true “first impression.” Accordingly, it’s important to put time and effort into developing and maintaining an updated, accurate resume.
Your goal should be to write your resume with both robots and humans in mind. Many organizations use Applicant Tracking Systems to sort and vet resumes, before hiring managers ever take a look at them. This means that you could have the best experience and qualifications in a whole field of candidates, and a pretty decent resume besides, but your information will fall through the cracks if your resume doesn’t contain the right keywords. Good keywords will refer not only to your experience but to the job description in the posting as well.