What is the Apollo Client?
Answer
Apollo Client is a comprehensive state management library for JavaScript that integrates with GraphQL. It handles: (1) Fetching: sending queries and mutations to a GraphQL server. (2) Caching: a normalized in-memory cache that automatically stores query results and updates UI when data changes. (3) Local state: managing local application state alongside server data. (4) React integration: hooks like useQuery, useMutation, useSubscription. (5) Optimistic UI: immediately updating the UI before the server responds. (6) Pagination: cursor-based and offset pagination helpers. Setup: wrap your app in ApolloProvider with an ApolloClient instance. Apollo Client works with React, Angular, Vue, and plain JavaScript. Alternatives include urql (lighter) and Relay (more opinionated).