Classify caching strategies

Caching speeds up an application by serving stored results instead of recomputing them, and good systems cache at three layers. Edge caching with CloudFront caches static, widely shared content at edge locations close to users. Application caching keeps hot objects in a warm function's own memory between invocations. Data caching with ElastiCache or DAX is a shared in-memory store for hot reads like sessions or query results. Match each scenario to the right cache layer.