JobPosting (schema.org)
JobPosting is a schema.org type that marks up job adverts in a structured way, with details such as job title, location, salary range and type of employment, which makes them eligible for the dedicated Google job search (Google for Jobs).
In practice
JobPosting is relevant not only to dedicated job boards but to every company page with open positions, for instance the careers section of your own website. It is important to remove expired adverts promptly or mark them with validThrough, because outdated entries can otherwise continue to appear in job search.