Classic industrial robots are locked behind cages because they move fast and would not notice a person. A cobot instead has rounded surfaces, no pinch points, torque sensing in its joints and software limits on force and speed. If it touches a hand, it stops.
Safety standards define several ways of collaborating: a safety-rated monitored stop, hand guiding, speed and separation monitoring (the robot slows as a person comes closer) and power and force limiting (the cobot mode people usually mean).
Important detail: no robot is safe by itself. A cobot holding a knife, a hot glue gun or a sharp sheet-metal part can still injure someone, so the installed application must pass a risk assessment. Typical uses are machine tending, screwdriving and palletising in small workshops.
