Properly written job position descriptions are often the only document that totally define what a role is, what skills are required to perform it, and where the role fits in an organization. This makes it simple to identify candidates that are a good fit for the role and also to hold candidates accountable if they are not performing essential duties that are required in the role.
A job description is an internal document that clearly states the essential job requirements, job duties, responsibilities, and skills required to perform a specific role. A more detailed job description will cover how success is measured in the role so it can be used during performance evaluations. They are also known as a job specification, JD, and position description (job PD).