Java Fundamentals: the Java language

Java is a language closely associated with object orientation, portability, and execution through the JVM.

Java and the object-oriented paradigm

There are several languages that allow applying Object-Oriented Programming.

One of the best known is the Java language.

Java became strongly associated with OOP because its way of structuring programs revolves largely around classes, objects, methods, attributes, and relationships between entities.

Origin and context

Java was publicly introduced in 1995 by Sun Microsystems.

The idea behind the language was tied to creating software capable of running in different environments, including devices and computers with distinct characteristics.

This context helps explain why portability became one of Java’s strongest trademarks.

Java and the internet

With the growth of the internet, Java gained a lot of attention.

For a period, it was used in features embedded in web pages, at a time when the web was still evolving rapidly.

Today, many of those old uses are no longer common, but Java remained relevant in other areas, mainly in enterprise systems, backend applications, APIs, banking systems, and large-scale applications.

How Java works in general

The basic flow is this:

1. The programmer writes Java code.
2. That code is compiled.
3. Compilation generates .class files.
4. These files contain bytecodes.
5. The JVM executes those bytecodes in the environment where it is installed.

In other words, Java code is not executed directly by the operating system the same way a regular native program is.

It goes through an intermediate layer: the JVM, short for Java Virtual Machine.

The role of the JVM

The JVM is responsible for executing Java bytecode.

As an initial explanation, we can say that it interprets this intermediate code.

More precisely, modern JVMs can also optimize and compile parts of the program at runtime, depending on the implementation and the application’s behavior.

For this first contact with Java, the main point is understanding that the JVM creates a layer between the Java program and the operating system.

Why this mattered

This structure helped Java be used in different environments.

Instead of depending directly on a single operating system or a single hardware architecture, the Java program depends on a compatible JVM installed in that environment.

This strengthened the idea of writing a program and running it on different platforms.

Summary

Java is a programming language strongly tied to object orientation and portability.

How it works involves compiling source code into bytecode and executing that bytecode on the JVM.

This combination helped Java become a widely used language in large systems, backend applications, and enterprise environments.