A data mart is a subset of a data warehouse that is usually oriented to a specific business line or team. Whereas data warehouses have enterprise-wide depth, data marts are often smaller sections of data warehouses segmented for specific uses. Here are some key points about data marts:

1. **Purpose-Oriented**: Data marts are designed to meet the specific needs of a particular group of users, such as a department within a company, like sales, finance, or marketing. They contain data relevant to that group.

2. **Scope and Size**: They are smaller in scope and size compared to data warehouses. This makes them easier to implement and manage.

3. **Data Sources**: Data marts can draw data from a wide range of sources. They may pull data from internal systems like ERP and CRM, as well as external data sources.

4. **Performance**: Because of their smaller size and focused nature, data marts can improve query performance. They enable users to access and analyze relevant data more quickly and efficiently than sifting through a larger data warehouse.

5. **Types of Data Marts**: There are two main types: independent data marts, which are created without a data warehouse and rely solely on data from source systems; and dependent data marts, which are created from an existing data warehouse.

6. **Implementation**: Implementing a data mart is generally faster and less costly than a full data warehouse because of its limited scope.

7. **Business Intelligence**: Data marts are often used in business intelligence (BI) applications, where they provide the data for reporting and analysis tools.

8. **Customization**: They can be customized to fit the specific needs of different user groups within an organization, providing more relevant and tailored data for analysis.

In summary, data marts are a focused and scaled-down version of data warehouses, designed to provide specific groups within an organization with the data they need for analysis and decision-making.

https://community.databricks.com/t5/data-engineering/how-to-build-data-warehouses-and-data-marts-with-python/td-p/42843