GraphQL and REST represent different API design philosophies. REST uses multiple endpoints for different resources with fixed response structures. GraphQL provides a single endpoint where clients specify exact data requirements. REST's over-fetching problem sends more data than needed; under-fetching requires multiple requests. GraphQL solves both with declarative data fetching. REST has mature tooling and caching mechanisms. GraphQL requires more complex server-side implementation. REST uses HTTP methods (GET, POST, PUT, DELETE) for operations. GraphQL uses queries, mutations, and subscriptions. REST caching is straightforward with HTTP caching headers. GraphQL caching requires more advanced solutions like Apollo Client. REST versioning often uses URL or header versioning. GraphQL evolves without versioning through deprecation. REST is simpler for straightforward CRUD operations. GraphQL excels when clients have diverse data requirements. REST has better tooling for monitoring and debugging. GraphQL provides strong typing through its schema definition language. Consider REST for simple APIs and GraphQL for complex data requirements. Many applications benefit from using both approaches.