# Overview of Parent Segments

Parent Segments provides an interface that professionals, who are not database designers or developers, can use to define a data model for customer data. You can use Parent Segments to manage, unify, consolidate, organize, and link data from all your Treasure Data tables.

In Parent Segments, you unify your customer data. When the customer data is unified, you can create customer segments without writing any SQL queries. You can personalize customer communications and conversations of any size and in any channel.

## Attributes and Behaviors

It is possible to have all attributes and behaviors for the parent segment contained within one parent table. However, it is typically specified using the following types of tables:

* Parent Table
* Attribute Tables
* Behavior Tables


Attributes and behaviors are often linked by a common ID (typically the td_global_id or `Customer ID`).

| Table type | Description | Example |
|  --- | --- | --- |
| Parent | Contains a master list of profiles. The list is typically imported from a CRM system. | First NameLast NameEmailCookie ID (most commonly the [Anonymous Visitor IDs](/products/customer-data-platform/integration-hub/streaming/td-javascript-sdk/anonymous-visitor-ids-with-javascript-sdk)) |
| Attribute | Contains additional attributes of the Parent Segment, and enriches the information in `Parent Table`. | Demographic Information:- age- gender- income- interests |
| Behavior | Contains the behaviors of the customers. | Website VisitsPurchase LogsSupport InquiriesDevice Usage Logs |


The following schema diagram is an example of all three tables and how they are linked:

![](/assets/master-segment-example-1.7f27009c9acfcac39e96522df86272a8dfdab5945ded5ad0814987c340b53731.142841d8.png)

The following table schema is an example of an attribute table and behavior table linked by customer ID.

![](/assets/master-segment-example-2.98776d9d15d7a62e9350977e21c25e0bd3a4cf6f947d6d5ef7c54da668256592.142841d8.png)

## System-Generated Entities in Master Segment

Master Segments automatically creates entities within your accounts. Do not edit or modify these system-generated entities, otherwise the creation process will fail. Example master segment system-generated entities:

* Database: cdp_audience_(AUDIENCE_ID)
  * Table: customers
  * Table: partitioned_customers
  * Table: behavior_(XYZ)
  * Table: activities
  * Table: cdp_new_web_access_(SEGMENT_ID)
* Workflow: cdp_audience_(AUDIENCE_ID)


## Parent Segment Data Enrichment

In Parent Segments, you can enrich your data by adding specific td_ columns to either the attribute or behavior tables. The inclusion of one of the following td_ columns triggers some automatic actions by Treasure Data:

Attribute

* td_client_id
* td_ip
* td_host
* td_path
* td_title
* td_description


Behavior

* td_user_agent
* td_url
* td_ip