# Snap / X:act

Snap chains and X:act anchors form the persistent transaction backbone
of the ecosystem.

An X:act directory represents an event entering the system, often
triggered by an incoming image or message. Snap chains connect related
events and transformations, allowing builders and automation processes
to understand lineage and processing stages.

Key structural roles: Tack -- subject anchor Shot -- individual event or
image instance

These structures allow distributed builders to process work
asynchronously while preserving a complete historical chain.