👉 GraphQL = Graph Query Language

It is a query language for APIs and a runtime for executing those queries.
💡 Created by Facebook (2012) and open-sourced in 2015.

Instead of multiple API calls (like in REST), GraphQL lets you:

• Ask exactly what you need 📦

• Get all data in a single request ⚡

• Avoid over-fetching or under-fetching 🔥

⚖️ GraphQL vs REST

🧩 Key Building Blocks of GraphQL

1️⃣ Schema 📜

Defines the shape of data (like a contract).

• Types: Query, Mutation, Subscription

type User {
  id: ID!
  name: String!
  age: Int
}

2️⃣ Query ❓

Used to fetch data.

query {
  user(id: 1) {
    name
    age
  }
}

👉 Only returns name & age (not the whole user object).

3️⃣ Mutation 🔄

Used to write/update/delete data.

mutation {
  createUser(name: "Abhi", age: 30) {
    id
    name
  }
}

4️⃣ Subscription 🔔

Used for real-time updates (like chats, stock prices).

subscription {
  newMessage {
    id
    content
  }
}

🌟 Advantages of GraphQL

✅ Precise data fetching – no extra baggage
✅ Single endpoint – easy integration
✅ Strongly typed schema – predictable responses
✅ Great for mobile apps – reduces data usage 📱
✅ Real-time capabilities with subscriptions ⚡

⚠️ Challenges of GraphQL

⚡ More complex server setup
⚡ Caching is harder than REST
⚡ Security concerns (deep nested queries can overload server)
⚡ Learning curve 📚

🌈 Visual Flow of GraphQL

Client 📱 → sends query 🎯 → GraphQL Server 🔮 → fetches from DB 📂 → returns only what client asked ✨

📌 Real-Life Example

Imagine you want a user profile page:

• In REST, you may need 3 calls: /user/1, /user/1/posts, /user/1/friends.

• In GraphQL, you just write:

query {
  user(id: 1) {
    name
    posts {
      title
    }
    friends {
      name
    }
  }
}

👉 And BOOM! 💥 You get all data in one request.

🎨 In simple words:
GraphQL is like going to a restaurant buffet 🍲 and telling the chef:
💬 "I only want 2 slices of pizza 🍕 and 1 bowl of salad 🥗"
Instead of REST where they serve you the whole buffet whether you need it or not. 😅