Glossary

Plain-English definitions of the vaping terms that come up most often. For a fuller explanation of mouth-to-lung and direct-to-lung vaping specifically, read MTL and DTL: what do these terms actually mean?

Airflow

The adjustable vent on a tank or pod that controls how much air mixes with vapour on the draw. More open airflow gives a looser, airier DTL-style pull; more restricted airflow gives a tighter MTL-style pull.

Chain vaping

Taking puffs back-to-back with little or no gap between them, so the coil doesn't get time to re-soak with e-liquid. A common cause of dry, burnt-tasting hits.

Coil

The replaceable part inside a tank or pod that contains a length of resistance wire wrapped around (or through) a cotton wick. It heats the e-liquid to produce vapour and wears out over time.

DTL (direct-to-lung)

A vaping style where vapour is pulled straight into the lungs in one motion, similar to a deep breath. Typically used with sub-ohm coils, looser airflow and higher-VG e-liquid.

Dry hit

An unpleasant, scorched-tasting puff caused by the wick not having enough e-liquid on it when the coil fires. A sign to check e-liquid level, priming, or coil age.

E-liquid

The liquid that's vaporised in a vape device, generally made up of propylene glycol (PG), vegetable glycerine (VG), flavourings, and optionally nicotine. UK-regulated nicotine e-liquid is capped at 20mg/ml.

Freebase (nicotine)

The traditional form of nicotine used in e-liquids before nic salts became common. It tends to feel harsher at higher strengths, which is why freebase e-liquids are usually sold at lower nicotine strengths than nic salts.

MTL (mouth-to-lung)

A vaping style where vapour is drawn into the mouth first, then inhaled into the lungs, similar to smoking a cigarette. Typically used with higher-resistance coils and tighter airflow.

Nic salt

A form of nicotine (nicotine salt) that's smoother on the throat at higher strengths than freebase nicotine, which is why nic salt e-liquids are popular in the lower-power pod kits many ex-smokers start with.

Ohms

The unit of electrical resistance printed on a coil (for example 0.4Ω or 1.2Ω). Lower resistance coils generally run at higher wattage and produce warmer, more vapour-dense hits; higher resistance coils suit lower-power MTL vaping.

Pod kit

A small, simple vape device that uses a refillable or replaceable pod instead of a separate tank. Most modern UK pod kits are rechargeable and refillable, since single-use disposable vapes were banned from sale from 1 June 2025.

Priming (a coil)

Saturating a new coil's wick with e-liquid before first use, usually by dripping liquid directly onto the visible cotton and letting it sit for several minutes. Skipping this step is a common cause of a burnt first few puffs.

Sub-ohm

A coil with resistance below 1.0 ohm. Sub-ohm coils need more power and higher-VG e-liquid, and are generally paired with DTL, looser-airflow devices rather than tight MTL pod kits.

Wattage

The power a device sends to the coil, shown in watts (W). Every coil has a manufacturer-recommended wattage range printed on it or its packaging; running above that range accelerates wear and increases the risk of a burnt taste.