Water is a great solvent. It’s neutral and doesn’t provide any strong positive or negative effects. It just helps components to mix better and to transport active components.
Propylene Glycol is a useful componet with many positive effects. It’s a very good moisturizer. It helps to deliver ingredients into deeper layers of the skin. It creates a protective layer on the skin preventing water loss. The component is researched very well and doesn’t have notable side effects. It’s used even for making food.
Fragrance is a mix of chemical ingredients (usually 20-30 chemicals but up to 200 sometimes) that help the product to smell better. It can hide many bad things. Synthetic fragrances may contain many different chemicals, but manufacturers don’t want to reveal each of them for some reason and hide them behind the word "Fragrance".
Lactic Acid is the most popular and the least aggressive acid among all the AHAs. Unlike Salicylic and Glycolic acids which can irritate your skin, Lactic Acid will hardly cause any problems. The combination of its soft action and effectiveness makes it a real brilliant. It exfoliates dead cells, makes the skin tone even, clears pores, kills bacteria, moisturizes the skin and helps to keep water, helps the cells to produce Hyaluronic Acid. It also works as a strong antioxidant and anti-aging component.
It's a great acid for getting familiar with the world of AHAs. If you want to start using "fruit acids" but struggling for some reason, try to use Lactic Acid first. If your skin accepts it well, you can try stronger acids.