Basically, a job board sells job offers or job details, while job search engines use a performance-based mechanism to advertise job offers. A job board is a website where employers and internal or external recruiters can post job offers. It's also the place where job seekers can search for and apply for job opportunities. Job boards are websites where employers post jobs directly to the board.
Job aggregators, on the other hand, are search engines that collect job offers from a wide range of websites, including job boards, in a single searchable online interface. You'll find a wider variety of job offers on job search engines because they contain listings from multiple sources. A generalist job board reaches a wide and diverse audience in all industries, sectors and types of employment. Other specialized boards serve a segment of the labor market, such as entry-level jobs, summer jobs, or internships.
However, job boards seem to be a better option between the two, either from the perspective of the employer or from the perspective of a candidate. With each publication, job aggregators typically include information about the origin of each offer: employer websites, job boards, professional association websites, etc. The online hiring industry includes hiring companies, job search engines, job boards, and professional networking platforms. For that to happen, you must take advantage of all the resources at your disposal, not just job boards and search engines.
Therefore, you should be a job board instead of just restricting yourself to a search engine, if you want a large number of employers and candidates to use your services. Therefore, worksites in the U.S. States that provide services to the IT industry may have a different format than, for example, worksites in Europe that provide services to the oil and gas industry. Monster, the largest and most well-known job board, is a general meeting with offers in a wide range of industries.