In religious organizations, the laity consists of all members who are not part of the clergy, usually including any non-ordained members of religious orders, e.g. a nun or a lay brother. In both religious and wider secular usage, a layperson is a person who is not qualified in a given profession or does not have specific knowledge of a certain subject. The phrase "layman's terms" is used to refer to plain language that is understandable to the everyday person, as opposed to specialised terminology understood only by a professional.
The person stood in the pulpit wearing vestments is a cleric, whereas the people seated below are of the laity.