Responsible for rasterizing composited scenes.

Provides low-level implementation of Flutter’s core APIs
(for example, graphics, text layout, Dart runtime).

Exposes its functionality to the framework using the dart:ui API.

Integrates with a specific platform using the Engine’s Embedder API.

Embedder (source code)

Coordinates with the underlying operating system
for access to services like rendering surfaces,
accessibility, and input.

Manages the event loop.

Exposes platform-specific API to integrate the Embedder into apps.

Runner

Composes the pieces exposed by the platform-specific
API of the Embedder into an app package runnable on the target platform.

Part of app template generated by flutter create,
owned by app developer.

Reactive user interfaces