8 GraphQL concepts every dev should know

(and most can't explain all 8):

👇

1️⃣ Queries

↳ Used to read or fetch data. They represent the way clients can request specific data from a GraphQL server.

2️⃣ Mutations

↳ Used to change data. Similar to queries in syntax, but instead of just fetching data, mutations modify server-side data.

3️⃣ Subscriptions

↳ Used to receive real-time updates. They maintain a persistent connection to the server, allowing clients to be notified automatically when specific data changes.

4️⃣ Types

↳ The building blocks of every GraphQL API. They define the shape of the data through scalars, objects, enums, interfaces, and unions, giving the API its strongly-typed structure.

5️⃣ Fields

↳ The individual units of data on a type. Every query, mutation, and object is composed of fields, and each one returns either a scalar value or another type.

6️⃣ Schema Definition Language (SDL)

↳ The syntax used to write a GraphQL schema. It's human-readable and used to define types, queries, mutations, and the relationships between types.

7️⃣ GraphQL Schema

↳ The contract between the client and the server. It defines the capabilities of the API by specifying how the client can fetch and mutate data.

8️⃣ Resolvers

↳ Server-side functions that handle the fetching or manipulation of data for a particular field of a type in the schema. Each field on each type has a resolver function.

—

Master these 8 and the rest of GraphQL clicks into place — directives, fragments, dataloaders, federation, all of it.

Which one tripped you up the most when you were learning?