Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is one of the most widely used programming languages in the world, especially in enterprise, Android, and web development.

🌟 Key Highlights:

  • Developed by: James Gosling at Sun Microsystems (now owned by Oracle)

  • First released in: 1995

  • Platform: Write Once, Run Anywhere (WORA)


πŸ” Definition:

Java is a robust, secure, and platform-independent programming language that allows developers to build applications that can run on any device equipped with a Java Virtual Machine (JVM).


🎯 Why Learn Java?

FeatureDescription
πŸ”„ Platform-IndependentCode runs on any machine with JVM, no need to rewrite
πŸ” SecureBuilt-in security features for safe web and network apps
πŸ’‘ Simple & FamiliarEasy-to-understand syntax if you know C/C++
🧱 Object-OrientedEncourages modular, clean, and reusable code
⚙️ MultithreadedAllows concurrent execution for efficient programs
πŸ’Ό Industry UseUsed by top companies (Google, Amazon, Netflix) in enterprise systems

πŸ’‘ How Java Works

  1. Write code.java file

  2. Compile → Bytecode .class file using javac

  3. Run → JVM interprets .class file on any platform

✅ Java doesn't run directly on the operating system — it runs inside the Java Virtual Machine, making it truly platform-independent.


🧩 Where Java is Used?

  • πŸ“± Android Development

  • 🌐 Web Applications

  • πŸ’Ό Enterprise Software (Spring Framework)

  • πŸ•Ή️ Game Development

  • πŸ“Š Big Data & Analytics

  • 🌍 Internet of Things (IoT)


πŸ›  Real World Example

java
public class HelloWorld { public static void main(String[] args) { System.out.println("Hello, PrepCampusPlus!"); } }

This simple code prints a message. But behind the scenes, Java handles memory, platform differences, and execution — all seamlessly.


✅ Summary:

TopicDescription
Java TypeHigh-level, general-purpose
Programming ParadigmObject-Oriented
PlatformPlatform-independent via JVM
Use CasesMobile, Web, Desktop, Enterprise
First Appearance1995, by Sun Microsystems