Toner

Facial toner is basically the in-between skincare step. It's meant to be used after washing your face but before applying your serum. It should always be applied immediately after cleansing, since our skin needs to be returned to a balanced pH of 4.5-5.5. 

Sometimes, a toner can be called a tonic, a chemical exfoliator, or an essence, depending on its consistency and purpose.