Computer Science Basics for Beginners

💻 Web vs Mobile vs Desktop Apps

Not all apps are built the same way. Depending on the platform and target users, developers choose to build web apps, mobile apps, or desktop software. Each type has its own pros, cons, and use cases.

🌐 Web Applications

• Accessed through browsers (like Chrome, Firefox)
• No installation needed — runs online
• Built with HTML, CSS, JavaScript + Backend (Node, Django, etc.)
• Examples: Gmail, Facebook, Online Banking Portals

✅ Pros

• Platform-independent (runs on Windows, Mac, Android, etc.)
• Easy to update (no need for user action)
• No download/install required

❌ Cons

• Needs constant internet connection (for most apps)
• Limited access to hardware (camera, storage, etc.)
• Slower performance compared to native apps

📱 Mobile Applications

• Installed via Play Store (Android) or App Store (iOS)
• Built using Java/Kotlin (Android), Swift (iOS), or Flutter/React Native (cross-platform)
• Examples: WhatsApp, Instagram, Uber, Paytm

✅ Pros

• Better performance and smooth UI
• Can work offline (with local storage)
• Full access to device hardware (GPS, camera, Bluetooth, etc.)

❌ Cons

• Must be downloaded and installed
• Separate codebases for Android and iOS (unless cross-platform)
• Frequent updates can annoy users

🖥️ Desktop Applications

• Installed on laptops or PCs (Windows, macOS, Linux)
• Built using languages like C++, Java, Python, Electron.js
• Examples: MS Word, Adobe Photoshop, VS Code, VLC Player

✅ Pros

• Works offline completely
• Powerful performance and hardware control
• Ideal for software like games, design tools, IDEs

❌ Cons

• OS-dependent (Windows software won’t run on Mac without porting)
• Requires manual installation and updates
• Not easily accessible on mobile or browser

📊 Quick Comparison

📝 Practice Questions

1. Give 2 examples each of web, mobile, and desktop apps.
2. Why are mobile apps faster than web apps?
3. What are the disadvantages of desktop apps?
4. Which type of app is best for an e-commerce business and why?

✅ Coming Next

In the next chapter, we’ll explore What Happens When You Type a URL? — a deep dive into DNS, HTTP, and request-response lifecycle.