The JVM is the heart of the runtime. It is an abstract computing machine that:
| Term | Contains | Used by | |------|----------|---------| | | JVM + core libraries + class loader | End users to run Java apps | | JDK | JRE + compiler ( javac ) + debugger + tools | Developers to create Java apps | | JVM | Execution engine (only) | Inside the JRE | what is java runtime
The Java Runtime Environment (JRE) is a software layer that provides the necessary resources for executing Java applications. Unlike traditional compiled programs that run directly on the operating system (OS), Java programs run inside the JRE. This paper explains the core components of the JRE—the Java Virtual Machine (JVM), class libraries, and class loaders—and why this architecture enables Java’s defining feature: “Write Once, Run Anywhere” (WORA). The JVM is the heart of the runtime