# Intro to Java

**Formal Definition:** Java is a high-level, object-oriented programming language designed for versatility, readability, and portability. Developed by Sun Microsystems (now owned by Oracle) in 1995, Java is widely used for building platform-independent applications.

**Key feature include:**

1. **Platform independent**: Java follows “Write Once, Run Anywhere” (WORA). Java code is compiled into **bytecode** by the **Java Complier**, which is executed on any device with **JVM**(Java Virtual Machine).
    
2. **Object-Oriented**: Java has a feature of creating objects extensively, making it easier to model real-world entities. The core concepts include **Class, Object, Inheritance , Polymorphism, Abstraction, Encapsulation.**
    
3. **Robust** and **Secure**: Java provides **Strong memory management**, **exception handling** and **runtime checking** which makes it robust. Security features such as **Java Sandbox** and **bytecode verifier**, which protect against vulnerabilities.
    
4. **Multithreading**:  
    Java allows concurrent execution of threads, making it suitable for applications requiring parallelism.
    
5. **Dynamic and Extensible**:  
    Java can dynamically load classes and supports extensions via third-party libraries.
    

**Example:**

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

This example prints "Hello, World!" to the console.