When using the Context API, wrapping components with the "" component allows them to consume context values. The "" component provides a way for components within the tree to access and use context data provided by a parent "" component. This mechanism is fundamental for passing and retrieving context values in React applications.

In Redux, the function responsible for specifying how the state should change in response to dispatched actions is called a "reducer." A reducer takes the current state and an action as input and returns the new state based on the action type. It's a fundamental concept in Redux for managing state changes in a predictable manner.