who in charge of a court?

The judge is the boss.

In some states in some courts the Court Clerk is an elected constitutional officer with independent authority over the operation of the Court Clerks Office. Your eloquent query, "who in charge?" lacks sufficient detail to provide an intelligent response. So, let me ask, "Where be dat you aks?"

There are hierarchies or levels within the court system. local courts are presided over by district and regional federal courts, who are presided over by appellant courts up through supreme courts in the state or federal levels.

There are officers in charge at every level that help to maintain order and decorum in the court. However, within the halls of a particular court, the Judge is in charge of their courtroom.

The judge has absolute control. She is responsible only to the President Judge, who in turn is responsible only to the Supreme Court of the state. In most states, the President Judge of a court system has little actual power, besides complaining to the Supreme Court.

In the US, each individual court is ruled by the judge assigned to that court. In the Supreme Court of the US it is currently Chief Justice John Roberts.