# Traits

> The customer-identity fields — email, name, phone, location, birthdate — sent with an event or conversion, which AnyTrack normalizes and hashes so the conversion can be matched to a real person.

Traits — also called **customer traits** — are the customer-identity fields sent with an [event](/glossary/event) or [conversion](/glossary/conversion): email, first and last name, phone, birthdate, and address (city, state, zipcode, country). They are the customer-identity subset of [event attributes](/glossary/event-attributes), and AnyTrack normalizes and hashes them automatically so a conversion can be matched to a real person on the ad platform.

## Traits vs Event Attributes vs Customer Data

- [Event Attributes](/glossary/event-attributes) — the full umbrella (customer, product, and transaction data); traits are only the customer-identity slice.
- [Customer Data](/glossary/customer-data) — the underlying personal information; traits are the named parameters (`email`, `firstName`, …) that carry that information on an event.

## How AnyTrack uses traits

Traits are the single biggest lever on [Event Match Quality](/glossary/event-match-quality): the more of them you reliably send, the more confidently a platform like Meta can attribute the conversion and build accurate audiences. You never pre-hash them — AnyTrack formats and hashes each trait to the ad platform's spec before sending it through the [Conversion API](/glossary/conversion-api). Traits arrive either client-side in an [event snippet](/glossary/event-snippet), server-side in a [conversion payload](/glossary/conversion-payload), or automatically from a connected catalog integration.