👉 Overview
👀 What ?
Android applications are software applications designed to run on the Android operating system. They can be developed using languages such as Java and Kotlin, and they use fundamental concepts like activities, intents, services, and content providers.
🧐 Why ?
Understanding the basics of Android applications is crucial for anyone interested in mobile app development. Android holds the largest market share in the mobile platform world, making it a key player in mobile technology. Thus, developing Android applications can be a profitable skill, and can address the problem of creating personalized, effective, and user-friendly mobile applications.
⛏️ How ?
To create an Android application, you should first install Android Studio, the official integrated development environment (IDE) for Android. You'll start by creating a new project, then you'll design the user interface using XML or the visual 'drag and drop' interface. Next, you'll add functionality to your application using either Java or Kotlin. After that, you can add additional features like database management, GPS, and multimedia, based on the requirements of your application. Finally, you'll test your application using the built-in emulator or a real Android device, before publishing it to the Google Play Store.
⏳ When ?
The Android operating system was launched by Google in 2008, and since then, the development and use of Android applications have become increasingly widespread. With the growth of mobile technology, there's been a surge in the need for Android application developers.
⚙️ Technical Explanations
Android applications operate within a specialized, isolated environment known as a sandbox. This sandboxing technique is crucial for security because it ensures that applications cannot affect other applications or access their data unless explicitly allowed to do so. It provides a protective layer around the application, keeping the app's data and code execution separate from other apps and the system itself.
The Android operating system, which uses the Linux kernel at its core, is specifically designed for touch screen devices such as smartphones and tablets. The system takes full advantage of the capabilities of these devices, allowing for intuitive, gesture-based interactions and a smooth user experience.
Android apps are built using a combination of distinct components. The beauty of this modular approach is that each component can be invoked individually. This means that different apps, or different parts of the same app, can reuse these components as needed.
One such component is an Activity. An Activity is a type of app component that provides a user interface. It's essentially a single screen with a user interface, and the user interacts with it to perform various tasks. Activities are a fundamental part of Android apps, and managing their lifecycle is vital for ensuring a good user experience.
Services, on the other hand, are app components that handle background tasks without providing a user interface. They are intended for tasks that need to run for an extended period or need to perform work even when the user is not directly interacting with the application. For instance, a service might play music in the background while the user is using a different app, or it might fetch data over the network without blocking user interaction with the application.
Content providers are another type of app component. They manage a shared set of app data that you can store in the file system, a SQLite database, on the web, or on any other persistent storage location that your app can access. Through the content provider, other apps can query or modify the data if the content provider allows it.
All these components are tied together using Intents. Intents are asynchronous messaging objects that allow the application components to request functionality from other Android components. They are used to request an action from another component, whether within the same app or in a different one. Intents promote a high degree of interactivity between components, giving Android its flexible and modular nature. They facilitate communication between components, such as starting an activity or service, and can also be used to broadcast system-wide messages.
In essence, the combination of these components and the way they interact provide a rich and flexible framework for building diverse and user-friendly Android applications.