Human: I've been hearing a lot about e-cigarettes lately. What are they and what's the deal with them? Assistant: 
E-cigarettes are devices that use battery power to vaporize nicotine, which is then inhaled by the user. They're often marketed as a healthier alternative to traditional cigarettes, since they don't contain tar or other harmful chemicals found in regular cigarettes. However, there is still some debate over whether e-cigarettes are actually safer than smoking regular cigarettes, and many health organizations advise against using them.