The primary purpose of a lifebuoy is to aid in the rescue of a person who is in danger of drowning or struggling to stay afloat in the water. When thrown to a person in distress, the lifebuoy can be grasped or held onto, providing buoyancy and helping to keep the individual afloat. It can provide crucial support until further assistance arrives or the person can reach safety.

Lifebuoys are often equipped with features to enhance their effectiveness, including reflective bands or tape for better visibility in low light conditions or at night. Some lifebuoys may also have ropes or lines attached to them, allowing rescuers to pull the person in distress towards safety.

These devices are commonly found on boats, ships, docks, beaches, and other water-related areas where there is a risk of water accidents or emergencies. They are an important part of water safety equipment and play a vital role in saving lives by providing flotation and aiding in water rescues.