Runnable

Runnable is an adjective and noun meaning capable of being executed by a computer. It describes code units, packages, or images that have a defined entry point or can be invoked by a runtime.

In software development, a runnable artifact is something a runtime can execute: a program binary, a script with interpreter, a container image with an entrypoint, or a module with an API. A runnable may require dependencies and environment configuration.

In Java, Runnable is an interface in java.lang with run(). Implementors define the task; a Thread can be constructed with a Runnable to run concurrently. A Runnable is not a thread, but a unit of work. A common pattern is new Thread(runnable).start() or an ExecutorService.

In packaging, a runnable jar in Java has a manifest specifying Main-Class and can be launched with java -jar. In Unix-like systems, scripts with a shebang and execute permission are runnable; Windows executables likewise.

In modern deployment, runnable artifacts include container images with an entrypoint, or serverless functions that can be invoked. The term emphasizes executability rather than mere code. Related terms: executable, run-time, interpreter.