庭 here is short for
法庭 'court / tribunal division' (e.g.
民事庭 civil division,
刑事庭 criminal division).
庭长 heads such a division inside a court. Distinct from
院长 yuànzhǎng 'court president' (head of the whole
法院) and
审判长 shěnpànzhǎng 'presiding judge of a specific panel.'