Strictly, only one distance is ever in perfect focus. Depth of field is the zone on either side of it where the softness is too small for the eye to notice. That zone can be a few millimetres in a macro shot or effectively infinite in a stopped-down landscape.
Three things set it: aperture, focal length, and how close you are to your subject. Wide apertures shrink it, long lenses shrink it, and moving closer shrinks it. Stack all three — an 85mm lens wide open, a foot from a face — and the eyelashes are sharp while the ears are already going soft.
Shallow depth of field is the fastest way to say this is the subject, which is why it reads as cinematic. But deep focus is a choice too: it keeps a subject legible inside their environment, and much of documentary and street photography depends on it. The mistake is treating blur as automatically better rather than as a tool with a specific job.