Objective:
This lesson will help you understand what Java is, why it’s popular, how it works, and what you need to start learning it.

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1. What is Java?

Java is a programming language created in 1995 by James Gosling and his team at Sun Microsystems.

• Why was Java created?
  It was made to create programs that can work on any computer or device.
• What makes Java special?
  • Java programs don’t depend on the operating system (like Windows or Linux).
  • Once written, they can run anywhere using the Java Virtual Machine (JVM).

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2. Why is Java Popular?

• Used Everywhere:
  Java is used to make websites, mobile apps, desktop software, games, and even large-scale systems like banking applications.
• Easy to Learn:
  Java’s structure is simple, so beginners can learn it quickly.
• Reliable:
  Java automatically manages memory and protects your computer from harmful programs.
• Platform-Independent:
  You don’t need to rewrite your program for different operating systems.

3. Real-Life Uses of Java

Here are some real-world applications of Java:

• Mobile Apps: Most Android apps are built using Java.
• Websites: Java powers big websites like LinkedIn and Amazon.
• Banking Systems: Java helps manage secure financial transactions.
• Games: Many games and gaming frameworks (like Minecraft and LibGDX) are built with Java.
• Scientific Tools: Researchers use Java to build software for analyzing data.

4. Features of Java

• Object-Oriented:
  Java organizes programs using objects (real-world ideas) to make the code reusable and easier to maintain.
• Secure:
  Java has built-in features to keep your data and computer safe.
• Fast:
  Java is designed to run faster using a Just-In-Time (JIT) compiler.
• Multithreaded:
  Java can handle multiple tasks at the same time.
• Robust (Strong):
  Java can handle errors well and manages memory automatically.

5. Why Learn Java?

• Job Opportunities: Java is widely used in industries like banking, e-commerce, and software development.
• Versatility: Suitable for desktop, web, mobile, and enterprise solutions.
• Community Support: Large developer community, extensive documentation, and resources.
• Long-Term Stability: Trusted by organizations for its reliability and backwards compatibility.

6. Java’s Place in the Tech Ecosystem

• Comparison with Other Languages:
  • C++: Java is simpler (no explicit pointers) and safer (automatic garbage collection).
  • Python: Java is faster and offers better control in enterprise-level applications.
  • C#: Both are similar but Java is more platform-independent.
• Frameworks and Tools Powered by Java:
  • Spring, Hibernate (for enterprise applications).
  • Android Studio (for mobile app development).
  • Apache Kafka, Hadoop (for big data and distributed systems).

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7. How Java Works

1. You Write the Code:
   You create your program in a file with the .java extension.
2. Java Compiles the Code:
   Your code is converted into a form called bytecode that the computer can understand.
3. The JVM Runs the Code:
   The Java Virtual Machine (JVM) runs the bytecode, so your program works on any computer or device.

8. What Do JVM, JRE, and JDK Mean?

• JVM (Java Virtual Machine):
  It runs Java programs and makes them work on any computer.
• JRE (Java Runtime Environment):
  It includes the JVM and tools to run Java programs.
• JDK (Java Development Kit):
  This is for developers. It includes tools to write, compile, and test Java programs.

9. What Do You Need to Start?

• Basic Computer Skills:
  You don’t need to know programming, but it helps if you understand basic computer operations.
• Tools:
  You will need the JDK to write and run Java programs.

10. Setting Up Java on Your Computer

1. Download the JDK:
   Visit the Oracle Java website and download the JDK for your system.
2. Install the JDK:
   Follow the instructions to install it.
3. Test the Installation:
   • Open a terminal or command prompt.
   • Type java -version to check if Java is installed.
   • Type javac -version to check if the Java compiler is working.

11.Activity

• Think: Can you guess which apps or websites you use might be built in Java?
• Homework:
  • Install the JDK on your computer.
  • Take a screenshot of the result of the java -version and javac -version commands.