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Types of Applications

Jun 29, 2025

Overview

This lecture introduces the concept of "apps" and examines different types of applications—desktop, mobile, and web—with a focus on the web platform as the primary context for modern application development.

What Is an App?

  • An app is computer software, usually a small and specific program, often used on mobile devices.
  • The term "app" originally applied to both desktop and mobile software, but has become more associated with small, downloadable programs.
  • Apps are typically designed to solve a specific problem or serve a particular function.

Types of Applications

  • Apps can be categorized by function (e.g., browsers, editors, word processors, social media).
  • Platforms for apps include desktops, mobiles (phones/tablets), and the web.

Desktop Applications

  • Desktop apps are typically standalone programs that may work without a network connection.
  • Examples: Microsoft Word, Visual Studio Code, Notepad, Gedit.
  • Many desktop apps use OS-specific Software Development Kits (SDKs).
  • Desktop apps often use local data storage and can work offline, with optional network use for specific tasks (e.g., email).

Mobile Applications

  • Mobile apps primarily target phones, with tablets as a secondary focus.
  • Mobile devices have limited memory, processing power, and rely on battery life.
  • Interaction differs: touch, audio, and camera-based interfaces replace keyboard and mouse.
  • Mobile apps may be OS-specific (e.g., iOS with Swift, Android), or cross-platform via special frameworks.
  • Most mobile apps are network-oriented, needing constant connectivity for full functionality.

Web Applications

  • Web apps are built to run within browsers, which are available across operating systems and devices.
  • The web offers a unified, OS-neutral platform for app development.
  • Web apps depend on network connectivity and leverage dynamic websites through technologies like JavaScript.
  • Web development is the course's primary focus due to its cross-platform potential and foundational principles.

Key Terms & Definitions

  • App — A small, specific software program, often for mobile devices.
  • SDK (Software Development Kit) — Tools and libraries for building applications on a specific OS or platform.
  • Browser — Software for accessing web content; a core platform for web apps.
  • Web App — An application that runs in a browser and often requires network connectivity.
  • Standalone — Software that operates independently, without needing external connectivity.
  • Cross-platform — Software that works on multiple operating systems with minimal changes.

Action Items / Next Steps

  • Develop familiarity with browsers, text editors, and terminals for upcoming coursework.
  • Prepare to explore web application development principles in depth.