A court usher is a position in a law court

Court

A court is a form of tribunal, often a governmental institution, with the authority to adjudicate legal disputes between parties and carry out the administration of justice in civil, criminal, and administrative matters in accordance with the rule of law...

. Tasks generally performed by court ushers involve escorting participants to the courtroom

Courtroom

A courtroom is the actual enclosed space in which a judge regularly holds court.The schedule of official court proceedings is called a docket; the term is also synonymous with a court's caseload as a whole.-Courtroom design:-United States:...

and seeing that they are suitably hydrated, as well as ensuring the secure transaction of legal documents within the court room and deciding the order of cases. The roles of an usher may vary from what type of court they are ushering.