E-liquids, also known as vape juice or e-juice, are the liquids used in electronic cigarettes and vaping devices to create vapor. They typically contain a blend of propylene glycol (PG), vegetable glycerin (VG), flavorings, and may or may not contain nicotine. E-liquids are available in a wide range of flavors and nicotine strengths, allowing users to choose options that match their preferences. The PG/VG ratio influences the vaping experience, with higher PG providing a stronger throat hit and higher VG producing denser vapor. Users should purchase e-liquids from reputable manufacturers, store them safely away from children and pets, and use them only with compatible vaping devices.