Query

/ˈɡræf.kjuː.ɛl/

n. “A smarter way to ask for exactly the data you need.”

GraphQL is a query language and runtime for APIs, originally developed by Facebook, that allows clients to request precisely the data they need from a server, no more and no less. Unlike traditional REST APIs, where endpoints return fixed structures, GraphQL gives clients the flexibility to shape responses, reducing over-fetching and under-fetching of data.

Key characteristics of GraphQL include:

• Declarative Queries: Clients specify exactly which fields they want, and the server responds with just that data.
• Single Endpoint: Unlike REST which often has multiple endpoints, GraphQL typically operates through a single endpoint that handles all queries and mutations.
• Strongly Typed Schema: The API is defined using a schema that specifies object types, fields, and relationships, enabling introspection and tooling support.
• Real-Time Capabilities: Supports subscriptions, allowing clients to receive updates when data changes.

Here’s a simple example of a GraphQL query to fetch user information:

query {
  user(id: "123") {
    id
    name
    email
  }
}

The server would respond with exactly the requested fields:

{
  "data": {
    "user": {
      "id": "123",
      "name": "Alice",
      "email": "alice@example.com"
    }
  }
}

In essence, GraphQL is a more efficient and flexible approach to APIs, giving clients precise control over data retrieval while maintaining a strongly typed, introspectable schema for developers.

/riˈækt ˈkwɛri/

n. “Data fetching without the drama.”

React Query is a data-fetching and state synchronization library for React applications. It simplifies the management of server state — that is, data that lives on a backend API or database — and keeps it in sync with the UI without the need for complex Redux setups or manual caching.

In typical React apps, fetching data from a REST or GraphQL endpoint involves writing boilerplate for loading states, error handling, caching, and refreshing. React Query abstracts all of that. When you request data, it automatically caches results, updates components reactively, refetches stale data in the background, and provides retry mechanisms for failed requests.

For example, consider a dashboard displaying user profiles from an API. Using React Query, you can call useQuery('users', fetchUsers) and immediately get an object containing data, isLoading, isError, and other properties. The library handles caching, background updates, and re-fetching when the window refocuses or network reconnects — all without you writing extra state logic.

React Query also supports mutations, which are actions that modify server data, like creating, updating, or deleting records. When a mutation occurs, queries depending on that data can be automatically invalidated and refetched to ensure the UI remains consistent.

One of the key benefits is declarative caching. Developers can control how long data stays fresh, when to refetch, and even share cached data between components. This reduces unnecessary network requests and improves performance while keeping the UI reactive.

The library integrates smoothly with other tools in the React ecosystem, including Redux, Context API, or React Router. It is particularly useful for SPAs where the same data is accessed across multiple components or pages.

In essence, React Query is not just a fetching library; it’s a data management solution. It reduces boilerplate, ensures consistency, and turns server data into a predictable, cache-friendly, and reactive source of truth — letting developers focus on building features rather than orchestrating network logic.