---
title: "Segments"
description: "Use server-calculated segment membership to target Experiences."
search:
  tags: ["sdk", "reference", "ios"]
  keywords: ["Swift", "StoreKit", "Xcode"]
---

Segments let you show an Experience to customers who meet specific conditions, such as people on a free plan who have reached an export limit. Define the audience in Nuxie; the SDK receives each customer's membership with their profile.

## How segment targeting works

Create a [Segment](/docs/guides/segments) and select it in the Experience's audience. Use `identify()` to send customer properties and `trigger()` to record the events its rules depend on. Nuxie calculates membership on the server and includes it in the customer profile.

For example, a segment for free-plan customers depends on a customer property such as `plan`. Send that property with `identify()` when the customer signs in or changes plan.

Segment-entry triggers can start a Journey on the server and prepare later steps for the app.

## Freshness

Membership changes become available after the relevant events or properties reach Nuxie and the SDK receives an updated profile. Profiles refresh at setup, on foreground return, and when the customer ID changes.

Calling `identify()` with new properties for the same customer sends those values without forcing a profile refresh. For an immediate in-app moment, use an [event trigger](/docs/guides/delivery); use a segment to define the audience.

## On-device entry gates

A Journey can require segment membership before starting a step. The SDK uses membership from the latest profile, so sending a local event does not immediately change the audience. This lets the same server-defined audience control delivery across the customer's devices.

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See [Segments](/docs/guides/segments) to define an audience and [Delivery](/docs/guides/delivery) to apply it to an Experience.