A job description or JD is a document that describes the general tasks, or other related duties, and responsibilities of a position. It may specify the functionary to whom the position reports, specifications such as the qualifications or skills needed by the person in the job, and a salary range. Job descriptions are usually narrative, but some may comprise a simple list of competencies; for instance, strategic human resource planning methodologies may be used to develop a competency architecture for an organization, from which job descriptions are built as a shortlist of competencies
Think of this as describing the purpose of the position, and its role within your company or organization as a whole. A job summary will briefly acknowledge the fundamentals of the position, so leave space on your job description template to answer.