# How to Use Block, Chain, and Flow

## Intent

Use `Block` for atomic units, `Chain` for ordered groups, and `Flow` for orchestration strategy.

## Quick Mapping

- `Block`: one function with optional retry/undo
- `Chain`: ordered composition of executable steps
- `Flow`: top-level execution plan and failure strategy

## Reference

See [Core Concepts](../core_concepts.md) and [API Reference](../api_reference.rst).