---
title: Runtime
description: How a scene script becomes a timeline, how frames resolve from it, and how actors host one another.
sidebar:
  hidden: true
---

A scene script runs once and records a timeline. A host then asks the compiled scene for
frames, in any order, and each answer depends on the frame alone.

## Scenes

**[Scene orchestration](/docs/runtime/scene-orchestration)**

The cursor, the timing verbs, spawning, inputs and compositions.

**[Compiled scenes](/docs/runtime/compiled-scene)**

Frame state, lookups, caching and reflection.

**[Determinism](/docs/runtime/determinism)**

What a frame may depend on.

## Structure

**[Slots](/docs/runtime/slots)**

Places an actor's users fill.

**[Children](/docs/runtime/children)**

Parts every instance has.