Java Overview
Welcome to the Java Overview page! If you’re new to Java or just need a refresher, this guide will walk you through the history, features, architecture, and importance of Java in the software world.
What is Java?
Java is a high-level, object-oriented, platform-independent programming language developed by Sun Microsystems in 1995 (now owned by Oracle Corporation). It is widely used for building:
- Desktop Applications
- Web Applications
- Mobile Applications (Android)
- Enterprise Systems
- Distributed Applications
- Cloud-based Microservices
Key Features of Java
Java is popular because of its robust and versatile nature. Here are its main features:
| Feature | Description |
|---|---|
| Simple | Easy to learn and write; follows C/C++ style syntax. |
| Object-Oriented | Everything in Java is treated as an object. |
| Platform-Independent | “Write Once, Run Anywhere” using the Java Virtual Machine (JVM). |
| Secure | Built-in security features like bytecode verification, security manager. |
| Robust | Strong memory management and exception handling. |
| Multithreaded | Supports concurrent execution using multithreading. |
| Portable | Java programs can run on any system without modification. |
| Distributed | Java supports RMI and networking capabilities for distributed apps. |
Java Architecture
Here’s a simplified breakdown of Java’s architecture:
- Source Code (.java) → Written by the developer.
- Compilation (javac) → Converts
.javato.class(bytecode). - JVM (Java Virtual Machine) → Executes bytecode on any platform.
JDK → JRE → JVM
- JDK: Java Development Kit – includes tools, compiler, and libraries for development.
- JRE: Java Runtime Environment – needed to run Java programs.
- JVM: Java Virtual Machine – the engine that executes Java bytecode.
Where is Java Used?
- Android App Development (Java was the official language before Kotlin)
- Enterprise Applications (banking systems, ERP software)
- Web Development (via frameworks like Spring Boot, JSP, Servlets)
- Cloud & Microservices (Dockerized Spring Boot apps)
- Scientific & Research Applications
Why Learn Java?
Java continues to be one of the most in-demand programming languages. Whether you’re preparing for a job interview, building your own project, or contributing to enterprise systems, Java is a foundational skill that opens many doors.