Differences styles.css and styles.base.css

What's the differnce betweeen styles.css and styles.base.css?

I've noticed there are duplicated enties in each file and I'm not sure the reason for both.

There is some info in this old post:

difference btw styles.css and styles.base.css

styles.base.css is the default styles for the entire cart.

styles.css is the styles specific to the skin you are using. It overwrites many of the default styles to create the look of the skin.