# Your audience

Learn how your audience is identified, how users are added to your project, where data comes from, and how to use that data for segmentation, personalization, and more.

## Contacts

A Contact is any user in your project. Within the Airship documentation, we use "user" and "Contact" interchangeably.

You can think of a Contact as a container that holds all the information about a person who can receive messages from you. This includes their devices, communication preferences, and any data you've collected about them. While a Contact can be associated with multiple devices, such as a user's tablet and phone, a device can only be associated with a single Contact.

A Contact can be in one of two states:

* **Anonymous Contact** — This is a user who hasn't been identified with a specific identifier from your system. Airship automatically creates an Anonymous Contact when someone first interacts with your app, website, or messaging channels. Anonymous Contacts still allow [Tags](https://www.airship.com/docs/reference/glossary/#tag), [Attributes](https://www.airship.com/docs/reference/glossary/#attributes), [Subscription Lists](https://www.airship.com/docs/reference/glossary/#subscription_list), and channel association.

* **Named User** — This is a user who has been identified with an identifier you provide, such as a customer ID or username from your system. This allows you to connect all of a person's devices and channels under one identity.
   
   Identifying a Contact as a Named User allows you to modify the Contact through Named User APIs and use the Named User ID for segmentation.

Airship can set targeting data on these identifiers, which are also used to map devices and channels to a specific user.

When a Contact goes from anonymous to named, the anonymous data automatically carries over to the Named User ID, if the Named User is new. If the Named User already exists, a conflict event is emitted by the SDK, and the app is responsible for migrating anonymous data to the existing Named User.

See [Named users](https://www.airship.com/docs/guides/audience/named-users/) for more information, including implementation steps.

## Channels

A channel is a specific device or communication method that belongs to a Contact. For example, a Contact might have an iOS device, an Android device, an email address, a phone number for SMS, or a web browser registered for web push. Each of these is a separate channel associated with that Contact.

A single Contact can have multiple channels, allowing you to reach the same person through different devices and communication methods. Each channel has a unique [Channel ID](https://www.airship.com/docs/reference/glossary/#channel_id) that Airship uses to identify and send messages to that specific device or communication method.

In another context, "channel" can refer to the communication media supported by the Airship Service: app, web, email, SMS, and Open Channels.

### Projects without Named Users

If you are not using Named Users, channels are automatically associated together through the SDK and [Opt-in Forms](https://www.airship.com/docs/reference/glossary/#opt_in_form). For instance, if a user submits their email address in a form in an app Scene, that email channel is added to the same Contact ID as the current app channel.

## Contact sources

Users enter your project when they interact with your brand through any of your communication channels. Each of these interactions creates a Contact in your project, even if the person hasn't logged in or provided their name yet.

The way users are added depends on which channel they use to connect with you:

* **Mobile apps** — When someone installs your iOS or Android app and opens it for the first time, the Airship SDK automatically creates a Contact and registers their device. If they opt in to push notifications, that channel is added to their Contact.
* **Web push** — When a visitor to your website clicks to allow push notifications, Airship creates a Contact and registers their web browser as a channel.
* **Email** — Users are added when they submit their email address through an [opt-in form](https://www.airship.com/docs/guides/messaging/features/opt-in-forms/) or [Scene](https://www.airship.com/docs/reference/glossary/#scene), when you register them manually, or through other methods. Each email address becomes a channel associated with a Contact. See [Register users](https://www.airship.com/docs/developer/api-integrations/email/getting-started/#register-users) in *Getting Started* for email.
* **SMS** — Users are added when they text a keyword to your SMS number, submit their phone number through an opt-in form or Scene, when you register them manually, or through other methods. Each phone number becomes a channel associated with a Contact. See [Register users](https://www.airship.com/docs/developer/api-integrations/sms/getting-started/#register-sms-users) in *Getting Started* for SMS.
* **Open Channels** — Users are added when you register them manually for channels like WhatsApp, Facebook Messenger, or other custom messaging platforms. See [Register channels](https://www.airship.com/docs/developer/api-integrations/open/getting-started/#register-a-channel-to-your-open-platform) in *Getting Started* for Open Channels.

## Data sources

User data can come from multiple sources:

* **Automatic collection** — Airship SDKs automatically gather basic information like device type, operating system, language, timezone, and country. This happens in the background when users interact with your app or website. See [Device properties](https://www.airship.com/docs/reference/data-collection/device-properties/).
* **User actions** — When users interact with your messages, make purchases, view content, or complete other activities, Airship records these as [Events](https://www.airship.com/docs/reference/glossary/#events) that become part of their profile.
* **Your systems** — You can send data from your CRM, e-commerce platform, or other business systems to Airship via APIs or CSV uploads. This might include customer IDs, purchase history, preferences, or demographic information.
* **User input** — Information users provide directly, such as when they fill out forms, answer survey questions in Scenes, or update preferences in a [Preference Center](https://www.airship.com/docs/reference/glossary/#preference_center).
* **External integrations** — Data from partner systems through integrations like Segment, Salesforce, or other platforms you've connected to Airship.

## Data storage

Contact-level data applies to the user across all their devices and channels. [Attributes](https://www.airship.com/docs/reference/glossary/#attributes), [Tags](https://www.airship.com/docs/reference/glossary/#tag), and [Lifecycle Lists](https://www.airship.com/docs/reference/glossary/#lifecycle_list) are stored at the Contact level.

Channel-level data is tied to a specific device or communication method. [Device Properties](https://www.airship.com/docs/reference/glossary/#device_properties), primary device Tags (Tags in the `device` tag group), and default [Events](https://www.airship.com/docs/reference/glossary/#events) are stored at the Channel level.

Some data types can be set at either the Contact or Channel level: predefined [Events](https://www.airship.com/docs/reference/glossary/#events), [Custom Events](https://www.airship.com/docs/reference/glossary/#custom_event), [Subscription Lists](https://www.airship.com/docs/reference/glossary/#subscription_list), and [Uploaded (Static) Lists](https://www.airship.com/docs/reference/glossary/#uploaded_list).

Events from any channel "roll up" to the Contact. This means that channel-level data is available for segmentation purposes for any Contact.

> **Note:** For projects using the channel-level segmentation system, custom Attributes and Tags can be set at either the channel or Contact level. For additional differences between systems, see [Channel-level segmentation](https://www.airship.com/docs/guides/audience/segmentation/segmentation/#channel-level-segmentation) in *Segmenting your audience*.


## Data management

You can manage user data in several ways:

* **Dashboard** — Upload CSV files to add or update user data in bulk, or use the [Contact Management](https://www.airship.com/docs/guides/audience/contact-management/) tool to view and manage individual users.
* **APIs** — Use Airship's REST APIs to programmatically add, update, or remove Tags, Attributes, and other data. This is useful for real-time updates from your systems.
* **SDKs** — Your mobile app or website can add or remove data directly using Airship SDK methods. This is ideal for capturing user actions as they happen.
* **Integrations** — Connected platforms like Segment or your CRM can automatically sync data to Airship.

You can remove data by:
* Setting Attributes to empty values or removing Tags
* Using the API to explicitly remove specific data points
* Resetting a Contact to clear all anonymous data, typically done when a user logs out

## Using audience data

User data powers many features in Airship that help you send more relevant, effective messages:

**Segmentation** — Divide your audience into groups based on their data. For example, you might create a [Segment](https://www.airship.com/docs/reference/glossary/#segment) of users who have made a purchase in the last 30 days, or users who live in a specific city. You can then send targeted messages to these Segments. You can create Segments based on:
* Attributes, such as age, location, or purchase history
* Tags, such as "premium_member" or "newsletter_subscriber"
* Events, such as "purchased" or "added_to_cart"
* Subscription lists
* Device properties
* Named User IDs

See [Segmenting your audience](https://www.airship.com/docs/guides/audience/segmentation/segmentation/).

**Personalization** — Customize message content for each individual user. Instead of sending "Hello!" to everyone, you can send "Hello, Sarah!" using the user's first name Attribute. You can personalize:
* Message text and subject lines
* Product recommendations based on purchase history
* Special offers based on loyalty tier
* Content based on location, language, or preferences

See [About personalization](https://www.airship.com/docs/guides/personalization/about/).

**Automation** — Trigger messages automatically based on user behavior or data changes. For example, send a welcome message when someone first opens your app, or a re-engagement message if they haven't visited in 30 days. See [Scenes](https://www.airship.com/docs/guides/features/messaging/scenes/scenes/), [In-App Automation](https://www.airship.com/docs/guides/features/messaging/in-app-automation/), and [About Automations and Sequences](https://www.airship.com/docs/guides/messaging/messages/sequences/about/).

**Channel Coordination** — When you have Named Users with multiple channels, Airship can help you choose the best channel to reach each person. For example, you might prefer to send messages to the channel they used most recently, or let users choose their preferred channel. See [Channel Coordination](https://www.airship.com/docs/guides/features/orchestration-experimentation/channel-coordination/).

**Analytics and insights** — Use user data to understand your audience better. See which segments are most engaged, which personalization strategies work best, and how user behavior changes over time. See [Reports & Analytics](https://www.airship.com/docs/guides/reports/).

**Advanced features** — User data also powers these advanced capabilities:
* [Predictive Analytics](https://www.airship.com/docs/guides/features/intelligence-ai/predictive/)
* [Audience Pulse](https://www.airship.com/docs/reference/glossary/#audience_pulse)
* [Journeys](https://www.airship.com/docs/reference/glossary/#journey)
* [Experimentation](https://www.airship.com/docs/guides/experimentation/)

The more complete and accurate your user data, the more effectively you can use these features to create meaningful, relevant experiences for your audience.