John Hopkins

Both smoking and vaping involve heating a substance and inhaling the resulting fumes. With traditional cigarettes, you inhale smoke from burning tobacco. With vaping, a device (typically a vape pen or a mod — an enhanced vape pen — that may look like a flash drive) heats up a liquid (called vape juice or e-liquid) until it turns into a vapor that you inhale.
“Vaping is a delivery system similar to a nebulizer, which people with asthma or other lung conditions may be familiar with,” says Broderick. “A nebulizer turns liquid medicine into a mist that patients breathe in. It’s a highly effective way of delivering medicine to the lungs.”