A wide picture angle corresponds to a wide area of view, while a small picture angle corresponds to a small area of view. Generally, when we refer to picture angle, we mean diagonal picture angle. This is the photographic zone of focus. For example, when focusing on someone facing the camera 1m ahead, the camera also focuses on everything within a specific zone extending from an imaginary line in front of that person to one behind the person. This zone circumscribes the camera's depth of field.
Depth of field depends on aperture, focal length, and shooting distance.