Component Lifecycle: Updating

React.memo works for class components while shouldComponentUpdate is for functional components
shouldComponentUpdate gives more control over the comparison logic
React.memo can only compare props, not state
A key difference is that React.memo can only compare props, not state, because it's designed for functional components which don't have their own state in the same way class components do. shouldComponentUpdate, on the other hand, allows class components to compare both next props and next state to current props and state to determine if re-rendering is necessary.
shouldComponentUpdate is deprecated in favor of React.memo