E-cigarettes are electronic devices that typically consist of several components. These include a battery, a heating element (often referred to as a coil), a reservoir or cartridge to hold the e-liquid, and sometimes a mouthpiece. The battery provides power to the heating element, which then heats the e-liquid to produce an aerosol that can be inhaled by the user.

The e-liquid, also known as vape juice or e-juice, is a mixture of ingredients that typically includes nicotine, propylene glycol (PG), vegetable glycerin (VG), flavorings, and other chemicals. When the e-liquid is heated, it turns into an aerosol that contains tiny particles and can be inhaled into the lungs.

E-cigarettes come in various shapes and sizes, with different designs and features. Some e-cigarettes are disposable, meaning they are used once and then discarded, while others are reusable and can be refilled with e-liquid. Some e-cigarettes have a button to activate the heating element, while others are draw-activated, meaning they are activated by inhaling on the mouthpiece. Some e-cigarettes also have adjustable settings, such as wattage or temperature, to customize the vaping experience.

The appearance of e-cigarettes can vary greatly. Some e-cigarettes are designed to resemble traditional cigarettes, cigars, or pipes, with a cylindrical shape and a mouthpiece that looks like a filter. Others may have a more modern and sleek design, resembling USB flash drives, pens, or other everyday objects. There are also larger devices known as tank systems or mods, which have a box-like shape and often allow for more advanced customization.

E-cigarettes are known by different names, reflecting their various shapes, sizes, and uses. Common terms used to refer to e-cigarettes include e-cigs, e-hookahs, mods (short for modifications), vape pens, vapes, tank systems, and electronic nicotine delivery systems (ENDS).

The act of using an e-cigarette is commonly referred to as "vaping." When a user takes a puff from an e-cigarette, the battery activates the heating element, which then heats the e-liquid to create an aerosol that is inhaled by the user. This aerosol is exhaled as a visible cloud, often referred to as "vapor," although it technically consists of tiny particles suspended in the air.

It's important to note that the long-term health effects of e-cigarettes are still being studied, and their safety and efficacy as a smoking cessation tool are a topic of ongoing debate among health experts. Regulations and laws regarding e-cigarettes vary by jurisdiction, and it's crucial to comply with local regulations when using these devices. If considering the use of e-cigarettes, it's important to carefully evaluate the potential risks and benefits, and seek professional advice if needed.