Final answer:
The Department of Labor is the federal department that publishes online copies of the Employment Law Guide. It deals with various labor-related aspects and sets it apart from the Department of Commerce and the Department of Education.
Step-by-step explanation:
The federal department responsible for publishing online copies of the Employment Law Guide is the Department of Labor. The Department of Labor manages various aspects related to labor, including employment standards, wages, and workplace safety. Although other departments, like the Department of Commerce and the Department of Education, also deal with workforce-related topics, they do not publish the Employment Law Guide; this is a specific responsibility of the Department of Labor.