Life jackets and Personal Flotation Devices are very similar. However, key differences exist between the two.
Life jackets are bulkier, less comfortable, and more regulated. They incorporate whistles, and come in two sizes, for people above and below 90 lb (40 kg). They’re commonly used in situations where emergencies may arise, as they work on unconscious people.
PFDs are sleeker, slimmer and easier to move around in. They’re preferred by aquatic athletes, such as kayak enthusiasts. They are less buoyant, though, and may require manual activation. Only people above 16 years old and 70 lb (32 kg) can use them.