A job specification could be considered a more precise job description that details the exact educational degrees, experience, skills, and requirements for a role. In most cases, these terms are used interchangeably and nearly always describe the same document.
A bank of job descriptions can be instrumental in supporting the development of other organizational documents and standards as well. Descriptions may offer a framework for developing performance evaluations. In addition, the information gleaned may provide a common thread for developing employee resumes, policy manuals, annual reports, and organizational media.