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.
Shea Butter is a great natural moisturizer everybody knows about. And it’s popular for a reason. It contains 5 essential fatty acids (palmitic, stearic, oleic, linoleic, and arachidonic), vitamins (A, D, E, F), and catechins, which are antioxidants. It moisturizes the skin and protects it from UV, cold, and other negative factors. It can be used on its own and will not harm your skin even in very high concentrations.
Butylene Glycol is a very popular synthetic alcohol. It helps the product to absorb deeper and faster. It is also a solvent for other ingredients. As for the skin benefits, it helps to attract water and helps to make the skin softer.
Unlike many other “Glycols”, it is not harmful and that's why it is used in many products. It was approved by US FDA and US EPA for usage.