Focus refers to the position at which rays of light passing through a lens converge to form a sharp, clear image on the film or digital sensor. Proper focus ensures that the subject appears crisp and well-defined within the frame.
Achieving accurate focus is fundamental in all types of photography, from portraits to landscapes, and can be controlled manually or automatically depending on the camera and lens system. Understanding focus allows photographers to direct viewers' attention, control depth of field, and produce professional-quality images with clarity and precision.