JVM (Java Virtual Machine)

Runs Java bytecode (like the engine):

• Loads and verify .class (bytecode) (security)

• Executes code

• Manages memory (Heap, Stack)

• Runs Garbage Collector

• Handles threads

• Have a predefined calling the class method:

  public static void main(string[] args)
  // can overload main method
  // predefined is to call this
  // JVM calls it based on class name (so must be static)
  

Platform-specific

• Windows JVM
• Linux JVM
• macOS JVM

// But bytecode is the same.

JRE (Java Runtime Environment)

JRE = JVM + core libraries (java.lang, java.util, java.io)