JavaJDK = JRE + compiler (javac) + tools (jdb, jstack, jmap)
JRE = JVM + standard libraries
JVM = bytecode executor + GC + JIT- JVM (Java Virtual Machine): thực thi bytecode, platform-specific (mỗi OS có JVM riêng), cung cấp runtime + GC + JIT.
- JRE (Java Runtime Environment): JVM + thư viện chuẩn. Chạy được app Java đã biên dịch, không biên dịch được.
- JDK (Java Development Kit): JRE + compiler
javac+ debugger + tools. Dùng để phát triển.
Flow: .java → javac (JDK) → .class bytecode → JVM thực thi.
2026: Java 9+ bỏ JRE riêng — chỉ phát hành JDK, dùng jlink để tạo runtime tối thiểu cho production (chỉ chứa module cần thiết, giảm size container).
JDK = JRE + compiler (javac) + tools (jdb, jstack, jmap)
JRE = JVM + standard libraries
JVM = bytecode executor + GC + JIT- JVM (Java Virtual Machine): executes bytecode, platform-specific (each OS has its own JVM), provides runtime + GC + JIT.
- JRE (Java Runtime Environment): JVM + standard libraries. Runs compiled Java programs, cannot compile.
- JDK (Java Development Kit): JRE + compiler
javac+ debugger + tools. Used for development.
Flow: .java → javac (JDK) → .class bytecode → JVM executes.
2026: Java 9+ stopped shipping a standalone JRE — only the JDK is published, use jlink to build a minimal runtime for production (only the modules you need, smaller container images).