Each process, or "runtime", applies different constraints to the code that runs in that process.
For example, each process has different supported JVMs and a different set of services available for dependency injection.

### Build session state

A "build session" represents a single invocation of Gradle, for example when you run `gradlew build`.
A session runs the build one or more times.
For example, when continuous build is enabled, the session may run the build many times, but when it is disabled, the session will run the build once only.

### Build infrastructure

Provides build logic, libraries, test suites and infrastructure to support developing and releasing Gradle.

### Documentation

Provides cross-cutting Gradle documentation and samples, along with the infrastructure to write, test, publish and host the documentation.

## Structure

Each platform and module has its own source directory under [platforms/](../platforms).

All source code in Gradle is written to target one or more of these runtimes.
Most source code targets the daemon and the remaining code either targets a single runtime, for example the Gradle client, or is shared across multiple runtimes.

## Composition by architecture modules

Each [architecture module and platform](platforms.md) can contribute code to any of the runtimes.