E cigarettes are battery-powered tubes that look like real cigarettes. But instead of inhaling and getting a lungful of tobacco smoke, you basically suck in vaporized nicotine. According to companies that make e cigarettes, since there’s no tobacco smoke, there are also none of the toxic ingredients that come with it, like tar and other cancer causing chemicals found in cigarettes. Instead, with e cigarettes you just get nicotine. E cigarette makers claim it’s similar to wearing a nicotine patch.