Computer Science Basics for Beginners

🔗 APIs & Databases (Overview)

Modern apps like https://udaanpath.com rely on APIs and databases to fetch, store, and share information. Whether you're filling a form, fetching job alerts, or submitting a quiz — APIs and databases are working behind the scenes.

🧠 What is an API?

API stands for Application Programming Interface. It is a bridge that allows two software systems to talk to each other.

Example: When you open https://udaanpath.com to check Sarkari results or Mandi Bhav, the front-end (browser) sends a request to an API, and the backend (server) responds with the latest data.

📦 Common API Actions:

• GET – Retrieve data (e.g., show job listings)
• POST – Submit data (e.g., submit a contact form)
• PUT – Update existing data
• DELETE – Remove data

💾 What is a Database?

A database is like a digital warehouse where data is stored in a structured way. It can store user profiles, job posts, results, course content, etc.

📚 Common Database Types:

• Relational (SQL): Data stored in tables (e.g., MySQL, PostgreSQL)
• NoSQL: Flexible document or key-value storage (e.g., MongoDB, Firebase)

🔗 Real-Life Example (UdaanPath)

Let’s say a user visits https://udaanpath.com/mandi-bhav and selects “Madhya Pradesh”.

• The browser sends a GET request to: /api/mandi-prices?state=MP
• The server processes the request, fetches prices from the database
• A JSON response is sent back
• The front-end displays the mandi bhav on screen

📈 API Response Example

{
  "state": "Madhya Pradesh",
  "market": "Mandsaur",
  "commodity": "Soybean",
  "price": "₹4,500 per quintal",
  "date": "2025-07-04"
}
  

🔐 Are APIs Secure?

APIs often use authentication (like API keys, OAuth tokens) to ensure only authorized apps/users can access data. At UdaanPath, we use secure HTTPS and validate every request.

📌 Key Concepts

• Request: Data sent from frontend to backend
• Response: Data sent back from server to frontend
• Endpoint: Specific API URL (e.g., /api/courses)
• JSON: Format used to exchange data (JavaScript Object Notation)

📝 Practice Questions

1. What is the role of an API in a web application?
2. How does a database differ from an API?
3. What are the advantages of using JSON in APIs?
4. Give an example of an API you’ve used recently (even unknowingly).

✅ Coming Next

In the next chapter, we’ll discuss Choosing the Right Programming Language — how to decide what language is best for your goals.