Definition: A skill set is a particular category of skills necessary to acquire a job. Examples of specific skill sets include human relations, research and planning, leadership, management and computer skills.
Skills can be considered soft (people) skills or hard (quantifiable and teachable) skills. Here's information on the difference between hard skills and soft skills.
Job listings often include a list of skill sets that applicants require. In your resume and cover letter, include skill sets that apply to the job listing. Here's a list of resume and cover letter keywords to use to describe your skills.
For example, if a position requires an applicant with strong computer skills, include a list of the software programs you are familiar with.
In addition, it's important to be prepared to share examples of the skill sets you have during job interviews. The closer a match your credentials are to the hiring criteria, the better your chances of getting a job offer.
Here's information on job specific skills including examples and how to promote them when applying for jobs.