Nicotine is an alkaloid and weak base. In nature, nicotine is found in nightshade plants (highest concentration in tobacco plants) and can be in freebase and pronated (ionized) form. Traditional e-liquid uses nicotine that has been de-pronated (freebased) for maximum biological absorption. However, vaping de-pronated nicotine in e-liquid at high concentrations causes unpleasant harshness in the throat due to the pH of freebase nicotine. By pronating nicotine, aka salt nicotine, you can inhale higher concentrations of nicotine, without the throat harshness. Nicotine salts in low wattage devices allow for vaping much higher concentrations of nicotine than freebase, and deliver a satisfactory throat hit and nicotine satisfaction which is very similar to a traditional cigarette.