A caching system is a technology that temporarily stores frequently accessed data to improve retrieval speed and efficiency. By keeping copies of this data closer to the user or application, caching reduces the time it takes to access information, which can enhance overall performance. Common examples of caching systems include web browsers, which store website data, and content delivery networks (CDNs), which cache content closer to users. Caching can be implemented at various levels, such as in-memory caches like Redis or Memcached, which store data in the server's RAM for quick access. This approach minimizes the need to repeatedly fetch data from slower storage systems, such as databases or external servers, thereby optimizing resource usage and reducing latency.