Why do grapes have skin?

Grapes have skin primarily for protection and to facilitate growth. The skin acts as a barrier against pests, diseases, and environmental factors, while also helping to retain moisture. Additionally, the skin contains important compounds, such as antioxidants and phenolics, that contribute to the grape's flavor and nutritional value. Lastly, the skin plays a crucial role in the fermentation process for wine production, influencing color, tannins, and overall taste.