Cocoa butter is obtained from the same bean that chocolate and cocoa come from. The butter is pressed from cocoa beans as a by-product of making chocolate. Cocoa butter is a very hard, saturated fat (solid oils, more stable) that is not easily absorbed by the skin. So when you use it, it's good to use it along with unsaturated oils (liquid, less stable) like olive oil or avocado oil, and this will make it absorb more easily into your skin.
Cocoa butter lays down a protective layer on your skin that holds moisture to your skin, making it a wonderful softener. The purest cocoa butter has a strong scent of chocolate.