A headshot is a tightly cropped business portrait used on LinkedIn or a company team page. It shows mainly the head and shoulders, and it should appear approachable and competent.
It is cropped tighter than a classic full-body or half-body portrait, which can show more of the body or the setting. A passport photo is purely formal, while a headshot is made for personal branding and lives online: as a profile picture, on an about page, in a speaker profile, or in a team overview.
Most people need one for their LinkedIn profile. Small companies increasingly use them on the about-us page and for a uniform team look, because a consistent set of portraits makes the whole company look more professional.