Java is a class-based, object-oriented programming language that's been widely used since 1995. Java's most famous concept is Write Once, Run Anywhere. This means that once you compile Java code, it can run on any machine that has a Java Virtual Machine (JVM) installed. A Java program written on Windows can also run on macOS/Linux, because the JVM acts as the middleman that makes that possible.
Java is used in a huge range of places—enterprise backends, Android development, school/university programming, banking systems, APIs, desktop tools, and more. What's important for beginners to know is that Java is a language that demands you follow its syntax precisely. Forget a semicolon, and Java basically says "you didn't respect me, did you?" and throws a compile error.
// The main entry point of a simple Java application
public class Main {
public static void main(String[] args) {
System.out.println("Java is powerful!");
}
}public class Main creates a class called Main. The main() method is where the program starts running. System.out.println() prints a line of text to the console.
Java is powerful!Real-world use
This pattern is the starting point for every Java application. Whether you're later writing a backend server, an Android app, or a CLI tool, you'll need to understand this entry point concept—where a program starts running.