Title: Data Dictionary Overview
Locale: en
URL: https://sensorswave.com/en/docs/data-center/data-dictionary/overview/
Description: Learn about the Data Dictionary's capabilities for managing events, properties, and their virtual extensions
The Data Dictionary is the data asset management center of Sensors Wave, providing unified viewing and management capabilities for all events and properties. Through the Data Dictionary, you can browse collected tracking data, create virtual events and virtual properties to extend analysis dimensions, and maintain display names and descriptions for your data assets.

The Data Dictionary helps you address the following questions:

- What events have been collected, and what properties does each event carry?
- Can multiple similar events be merged into a single unified analysis metric?
- Can new calculated fields be derived from existing properties without modifying tracking code?
- How to maintain display names and descriptions for events and properties so team members can quickly understand data definitions?

## Core Concepts

### Tracked vs. Virtual

Data assets in the Data Dictionary fall into two categories:

| Type | Source | Characteristics |
|------|--------|-----------------|
| **Tracked** | Actually collected via SDK or server-side API | Data is written to storage at collection time; this is raw data |
| **Virtual** | Defined through rules or expressions in the product interface | No new data is generated; dynamically computed at query time |

### Events and Properties

| Dimension | Description |
|-----------|-------------|
| **Event** | Describes a user action, such as "Page View", "Button Click", "Payment Success" |
| **Event Property** | Describes contextual information when an event occurs, such as "Page URL", "Button Name", "Payment Amount" |
| **User Property** | Describes user characteristics, such as "Registration Time", "City", "Membership Level" |

## Module Overview

| Module | Function | Typical Scenarios |
|--------|----------|-------------------|
| **Tracked Events** | View and manage SDK-collected events | Browse event list, edit display names, manage visibility |
| [Virtual Events](virtual-events.mdx) | Merge multiple tracked events into one logical event, or split one event by conditions | Merge "WeChat Payment" and "Alipay Payment" into "Payment Success" |
| **Tracked Properties** | View and manage event properties and user properties | Browse property list, check data types, edit descriptions |
| [Virtual Properties](virtual-properties.mdx) | Derive new event or user properties via SQL expressions | Calculate "Unit Price" = Order Amount / Item Count |

## Relationship with Other Modules

The Data Dictionary serves as the foundation for analytics and operations, working closely with other modules:

- **With Analytics**: Events and properties selected in Event Analysis, Retention Analysis, Funnel Analysis, and other models all come from the Data Dictionary. Virtual events and virtual properties can be used directly in all analysis models
- **With User Operations**: Cohort filtering conditions can use events and properties from the Data Dictionary, including virtual properties
- **With Data Integration**: Events and properties collected via SDK automatically appear in the Data Dictionary

## Next Steps

Choose a starting point based on your needs:

1. **[Virtual Events](virtual-events.mdx)**: If you want to merge multiple related events for analysis, or split a general event into more specific ones
2. **[Virtual Properties](virtual-properties.mdx)**: If you want to create calculated fields based on existing properties (supports both event and user properties)

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**Last updated**: April 3, 2026