There are two types of nicotine bases in e-liquids – Traditional and nicotine salts.
Traditional
Traditional is the original nicotine in e-liquids. It creates a strong throat hit, which can feel a bit too strong at super high nicotine strengths.
Traditional feels harsher on the throat, and suits people who prefer that feeling or who like to puff little and often throughout the day.
Nicotine salts
E-liquids with nicotine salts generally feel much smoother on the throat than Traditional products.
Nicotine salts is just normal nicotine that has been pH balanced. Correcting the pH levels of the nicotine takes away the harshness that you feel on the throat when inhaling.
These are good for people highly dependent on nicotine, or who don’t want to puff so many times and still get the hit.