What is the difference between a Group & Bundle?

Below is the definition for a Bundle and a Group:

Product Bundle – When you add a Bundle to an Opportunity, the total price of the components will be assigned to the Bundle Opportunity Product, and all components within the bundle have a $0 value.

Product Group – When you add a Group to an Opportunity, the price of each component will be assigned to the Opportunity Product, and the Group Opportunity Product has a $0 value.