What is Java?
Java is a powerful, object-oriented programming language developed by Sun Microsystems (now Oracle) in 1995. It follows the 'Write Once, Run Anywhere' principle — Java code compiled on one platform runs on any platform with a Java Virtual Machine (JVM).
Java is one of the most widely used programming languages, powering Android apps, enterprise systems, web backends, and more.
- Object-oriented with strong typing
- Platform independent via the JVM
- Automatic memory management (garbage collection)
- Rich standard library and ecosystem
- Used by Netflix, Google, Amazon, and most enterprises
Your First Java Program
Every Java program starts with a class. The main method is the entry point of execution.
Example
// HelloWorld.java
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}
// Compile: javac HelloWorld.java
// Run: java HelloWorld
// Output: Hello, World!