Java Development Overview

JRE (Java Runtime Environment)

• Primary purpose: Running Java programs on your computer
• Includes the JVM and the Java Standard Library
• Contains everything needed to run Java applications

Java Standard Library

• Provides essential classes and packages:
  • String - Text handling
  • Math - Mathematical operations
  • Exception & Throwable - Error handling
  • Object - Base class for all objects
  • java.util - Collections, date/time utilities
  • java.io - Input/output operations
  • java.sql - Database connectivity
  • Many more core packages and classes

JVM (Java Virtual Machine)

• Responsible for executing Java programs
• Loads compiled bytecode into memory and runs the program
• Ensures platform independence (write once, run anywhere)
• Handles memory management, garbage collection, and multi-threading

JDK (Java Development Kit)

• Used to create and build Java applications
• Includes everything in the JRE (which contains the JVM)
• Provides development tools:
  • javac - Compiles .java files into bytecode
  • Java library source code
  • Debugger for finding/fixing errors
  • Monitoring tools (e.g., JConsole)
  • JAR file creation utilities for packaging applications
  • Testing frameworks and additional development utilities

Note: The JVM takes your compiled Java class files and libraries, loads them into memory, and executes your program.

Would you like me to explain any of these components in more detail?