Hiring managers tend to make decisions based on certain information, or categories of information. One of those categories, hard skills, can be described as the technical information/abilities needed to perform a job. These are usually gained through training programs, certifications, on-the-job training and work experience.
In addition to hard skills, employers want to know about your soft skills. These can be shown on the job, or in your recommendations from co-workers, peers, supervisors, etc. and listed on your resume.