Runtime

The software environment that executes code: it provides core services, manages resources, and acts as the crucial abstraction layer between your program and the operating system.

A Runtime Environment (RTE) is the dedicated platform where a program’s compiled or interpreted code runs, abstracting away the underlying OS and hardware complexities. It handles critical operations: memory allocation (heap and stack), garbage collection, I/O access, and threading. For example, the Java Virtual Machine (JVM) executes Java bytecode, while Node.js and Bun utilize the V8 engine to run JavaScript outside of a browser. This environment ensures cross-platform compatibility and provides the necessary system interfaces (APIs) for your application to function correctly.

https://developer.mozilla.org/en-US/docs/Glossary/Runtime_environment