✅ 50 Must-Know Web Development Concepts for Interviews 🌐💼

📍 HTML Basics 
1. What is HTML? 
2. Semantic tags (article, section, nav) 
3. Forms and input types 
4. HTML5 features 
5. SEO-friendly structure 

📍 CSS Fundamentals 
6. CSS selectors & specificity 
7. Box model 
8. Flexbox 
9. Grid layout 
10. Media queries for responsive design 

📍 JavaScript Essentials
11. let vs const vs var 
12. Data types & type coercion 
13. DOM Manipulation 
14. Event handling 
15. Arrow functions 

📍 Advanced JavaScript 
16. Closures 
17. Hoisting 
18. Callbacks vs Promises 
19. async/await 
20. ES6+ features 

📍 Frontend Frameworks
21. React: props, state, hooks 
22. Vue: directives, computed properties 
23. Angular: components, services 
24. Component lifecycle 
25. Conditional rendering 

📍 Backend Basics
26. Node.js fundamentals 
27. Express.js routing 
28. Middleware functions 
29. REST API creation 
30. Error handling 

📍 Databases 
31. SQL vs NoSQL 
32. MongoDB basics 
33. CRUD operations 
34. Indexes & performance 
35. Data relationships 

📍 Authentication & Security 
36. Cookies vs LocalStorage 
37. JWT (JSON Web Token) 
38. HTTPS & SSL 
39. CORS 
40. XSS & CSRF protection 

📍 APIs & Web Services
41. REST vs GraphQL 
42. Fetch API 
43. Axios basics 
44. Status codes 
45. JSON handling 

📍 DevOps & Tools 
46. Git basics & GitHub 
47. CI/CD pipelines 
48. Docker (basics) 
49. Deployment (Netlify, Vercel, Heroku) 
50. Environment variables (.env)

💬 Tap ❤️ for more!