What's the difference between a baby swing and a bouncer?

Swings use a motor to provide sustained, repetitive motion (side-to-side, head-to-toe, or rotational) and typically run on AC power or batteries. Bouncers rely on the baby's own movement or a light vibration unit. Reviewers in r/beyondthebump and r/newborns note that swings tend to soothe colicky or fussy newborns more reliably, while bouncers are lighter, cheaper, and grow with the child longer.