Nic salts, freebase e-liquids and shortfills are the three main types of e-liquid sold in the UK, and the difference comes down to the form of nicotine and how the bottle is supplied. Nic salts use a salt form of nicotine that feels smoother at higher strengths and suit low-power mouth-to-lung pods. Freebase is the traditional form, usually sold at lower strengths in 10ml bottles. Shortfills are larger bottles of...