Explain how you would implement data caching in a JavaScript application to improve performance.

Data caching involves storing previously fetched data to avoid redundant requests. I would use techniques like memoization for function results, client-side caching with techniques such as Local Storage or IndexedDB, and server-side caching through HTTP caching headers

For dynamic content, implementing a cache expiration policy is essential to ensure data freshness. Choosing the appropriate caching strategy depends on the specific use case and data access patterns..