Clearing up the confusion.
Is the process of studying the duties and conditions of each job and the qualification which a person should posses to perform it. It refers to the formal process of collecting information about a job to identify the components involved in its performance.
It is a written statement outlining the purpose and the principle duties and responsibilities of a job and what a job holder does, how it's done and why it's done.
It refers to the written statement outlining the personnel qualifications that an individual should possess in order to perform the duties and responsibilities identified in job description. It states the minimum acceptable qualification that an employee must possess to perform the job successfully.