# Event Mapping

> The per-ad-platform rules that send a conversion out to each platform's matching conversion action, so one tracked conversion optimizes correctly everywhere.

**Event mapping** is the set of per-ad-platform rules that decide how a conversion is sent out to each platform's matching conversion action. It is the outbound half of how one tracked conversion stays consistent across Facebook, Google, TikTok, and others.

## Do not confuse with

- [Conversion Mapping](/glossary/conversion-mapping) — event mapping is *outbound* (conversion → each ad platform's action); conversion mapping is *inbound* (a source's events → a standard conversion). The defining pair.
- [Conversion API](/glossary/conversion-api) — event mapping is the routing *rule*; the Conversion API is the *channel* that physically delivers the event.

## In AnyTrack

After a conversion is normalized by [Conversion Mapping](/glossary/conversion-mapping), event mapping routes it outbound: a standard `Purchase` maps to Facebook `Purchase`, Google `purchase`, and TikTok `CompletePayment`. Custom conversions have no native platform equivalent, so event mapping is where you point each one at the right conversion action on every connected ad platform.