JAVA INTRODUCTION

1. How Java Started (1991)

• Java was created by James Gosling and his team at Sun Microsystems.

• Initially, it was called Oak 🌳.

• The goal: build software for electronics like TVs, set-top boxes.

2. Name Changed to Java (1995)

• The name Oak was already taken → changed to Java ☕.

• Inspired by coffee (Java coffee).

• Officially released in 1995.

👉 Famous slogan:

“Write Once, Run Anywhere” (WORA)
Means Java programs can run on any device using JVM.

🔑 Summary

• Created in 1991

• Released in 1995

• Founder: James Gosling

• Owned by Oracle today

• Famous for: Platform independence

             ## ARCHITECTURE OF JAVA
  

🔹 1. Java Source Code

• You write code in a .java file 👉 Example: Hello.java

🔹 2. Java Compiler (javac)

• Converts source code → bytecode

• Output file: .class

👉 Why bytecode?
Because it is platform independent

🔹 3. Bytecode

• Intermediate code (not machine code)

• Can run on any system with JVM

🔹 4. JVM (Java Virtual Machine)

👉 Most important part ⭐

• Converts bytecode → machine code

• Executes the program

JVM Components:

• Class Loader → loads class files

• Bytecode Verifier → checks security

• Interpreter → executes code line by line

• JIT Compiler → converts to faster native code

• Garbage Collector → removes unused memory