There are many different types of "e-cigarettes" and other devices used for vaping. Some look like real cigarettes, while others look like pens or other objects. This graphic shows some examples.
Reproduced from: Centers for Disease Control and Prevention. Quick facts on the risk of e-cigarettes for kids, teens, and young adults. https://www.cdc.gov/tobacco/basic_information/e-cigarettes/Quick-Facts-on-the-Risks-of-E-cigarettes-for-Kids-Teens-and-Young-Adults.html (Accessed on August 9, 2021).