A more thorough explanation:

An Administrative Law Judge (ALJ) is a judge who presides over official and unofficial hearings of administrative disputes in the Federal government. They are appointed by the heads of executive agencies and are considered part of the executive branch, not the judicial branch. ALJs carry out determinations on both questions of fact and questions of law, like bench trials for judicial proceedings, and they have the authority to issue subpoenas, administer oaths, and issue rulings.

For example, an ALJ may hear a dispute between a person and the Social Security Administration (SSA) regarding their eligibility for disability benefits. The ALJ would listen to both sides, review evidence, and make a decision based on the law and facts presented.

ALJs participate in many different topics and for many different agencies such as the Environmental Protection Agency (EPA) and the U.S. Postal Service. The determinations of an ALJ may be appealed potentially even to a federal judicial court. However, essentially every agency has its own appellate processes of review that must be followed before someone can access the federal courts.

It is important to note that ALJs do not serve the same role as administrative judges. Administrative judges can only participate in unofficial disputes of executive agencies which constitute the majority of administrative disputes. Only ALJs can hear official disputes heard by the agencies. Further, administrative judges are directly hired by the agencies and are subject to their employment rules and benefits, unlike the independent ALJ judges.

Many states also have ALJs that serve similar roles as their Federal counterparts. The rules and nature of ALJs vary by state on levels of neutrality, procedure, and jurisdiction.