# Tables

Your data is held in tables, one for each kind of thing your system records, such as households, people, and donations. Every [variable](<https://help.apteco.com/en/orbit/data/variables/index.md>) belongs to one of them. Your system's tables are set up when it's built, in FastStats Designer or [Orbit Connect](<https://help.apteco.com/en/orbit/connect/index.md>).

> [!TIP]
>
> In Orbit Connect, you can also choose how your variables are organised into folders, so they're easy to find in the data picker. See [Folder structure](<https://help.apteco.com/en/orbit/connect/system-builds/folder-structure/index.md>).

## How tables are arranged

Tables sit in a hierarchy. Each record in a table belongs to one record in the table above it. For example, each donation belongs to one person, and each person belongs to one household. The data picker's **Tables** tab shows the hierarchy as a tree.

The hierarchy affects what you can do with your data:

- **What you count**: The same filter gives different counts on different tables. Counting people and counting their donations give two different numbers.
- **Behaviours**: A [behaviour](<https://help.apteco.com/en/orbit/data/behaviours/#table-hierarchy-requirement>) needs a table of transactions below the table you're working with, such as donations below people
- **Expressions**: An expression can use variables from its own table, or from any table above it

## Choose a table to count its records

Choose a table on the **Tables** tab of the data picker when you want to count its records, or to group records by it. For example:

- A [measure](<https://help.apteco.com/en/orbit/dashboards/measures/index.md>) on a dashboard tile or workbook chart, such as the number of people
- The measure that a campaign [goal](<https://help.apteco.com/en/orbit/campaigns/journey-builder/goals/index.md>) tracks, such as the number of bookings
- **Per** on an [N per limit](<https://help.apteco.com/en/orbit/audiences/building-an-audience/limits/#n-per-limit>), to limit the number of records for each record of another table

> [!NOTE]
>
> **Example**
>
> A charity's dashboard is filtered to supporters in the North West. A number tile measuring the People table shows how many supporters that is. A second number tile, measuring the Donations table, shows how many donations those supporters have made.

## Other places you choose a table

Some features also ask which table to work at:

- An [audience's table level](<https://help.apteco.com/en/orbit/audiences/building-an-audience/#choose-a-table-level>) decides what the audience counts, such as people or transactions
- A dashboard tile counts through a table that its filters [resolve to](<https://help.apteco.com/en/orbit/dashboards/filtering/resolve-tables/index.md>)
- An expression's **Table**, on the picker's **Expression** tab, is the table it calculates a value for each record of