# GraphQL Compared With REST — GraphQL

Source: https://www.skillbyai.com/en/graphql/f-vs-rest

> One endpoint, client-shaped responses.

## Over-fetching and under-fetching

With REST, each resource has its own URL and a fixed response shape, so a screen often needs several requests (**under-fetching**) and receives fields it does not use (**over-fetching**). GraphQL, created at Facebook and now governed by the GraphQL Foundation, exposes a **typed schema** at a single endpoint; the client sends a query describing exactly which fields and related objects it wants, and the response mirrors that shape. The schema doubles as documentation and enables tooling such as autocomplete and code generation.

## Ask for exactly what you need

GraphQL lets clients describe the data they need in one request against a typed schema.

![Three ideas: GraphQL versus REST, the request model, when to use it.](assets/figures/graphql/section-1-map.svg) — Figure 1.1 — REST versus GraphQL, requests and fit.

## One screen, two approaches

Loading a user with recent orders and product names.

```text
REST:
  GET /users/42                    -> full user object (20 fields, we need 2)
  GET /users/42/orders?limit=3     -> 3 orders
  GET /products/7, /products/9 ... -> one request per product name

GraphQL (one request):
  POST /graphql
  { user(id: "42") { name orders(first: 3) { total items { product { name } } } } }
```

## A set menu versus ordering à la carte

REST serves set menus per endpoint; GraphQL lets each diner order exactly the dishes they want from one menu.

**Quiz:** What problem does GraphQL address directly?

- [ ] TLS encryption
- [ ] Database indexing
- [x] Over-fetching and under-fetching of data
- [ ] Container orchestration

*Answer:* Over-fetching and under-fetching of data. Clients choose the fields.