Web Development Interview Questions for Freshers

1. What happens when you type a URL in your browser and press Enter?
Answer:

DNS lookup happens to find the IP address

Browser sends an HTTP/HTTPS request to the server

Server processes and sends back HTML/CSS/JS

Browser renders the page using its rendering engine


2. What is the difference between GET and POST requests?
Answer:

GET: Sends data in the URL, used for fetching data

POST: Sends data in the body, used for submitting data securely


3. What is a responsive website?
Answer:
A responsive website adjusts layout and design based on screen size and device (mobile, tablet, desktop), usually using CSS media queries.

4. What is the role of Webpack in web development?
Answer:
Webpack bundles JavaScript files, CSS, and assets into optimized output for faster website loading and better performance.

5. What is the purpose of async and defer in script tags?
Answer:

async: Loads script asynchronously and executes it immediately

defer: Loads script asynchronously but executes after HTML is parsed


6. What is the difference between localStorage and sessionStorage?
Answer:

localStorage: Stores data with no expiration

sessionStorage: Stores data until the browser tab is closed


7. What is CORS?
Answer:
CORS (Cross-Origin Resource Sharing) is a browser security feature that restricts cross-domain API calls unless the server allows it.

8. What is the difference between null and undefined in JavaScript?
Answer:

undefined: A variable declared but not assigned a value

null: A variable explicitly set to have no value


9. How do you optimize website performance?
Answer:

Minify CSS/JS

Compress images

Use lazy loading

Use caching

Reduce HTTP requests

Use a CDN


10. What is the DOM?
Answer:
DOM (Document Object Model) represents the structure of an HTML document as objects, which JavaScript can interact with to change content dynamically.

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