First aid is immediate assistance given to someone who is injured or suddenly affected by an illness. It includes caring for life-threatening conditions and preventing further harm until professional medical help arrives. A first aid box contains supplies to treat common injuries and illnesses like bleeding, fractures, burns, and choking. It includes sterile dressings, bandages, antiseptic, gloves, and other protective equipment to safely provide first aid while preventing disease transmission. Proper precautions like wearing gloves and masks are essential for first aiders to avoid contact with blood or bodily fluids.