> ## Documentation Index > Fetch the complete documentation index at: https://docs.summation.com/llms.txt > Use this file to discover all available pages before exploring further. # Dimension table > A Summation table that defines a dimension other tables reference. A **dimension table** is a [Summation table](/features/tables) that defines a **dimension** — a key plus its attributes — that other tables reference. Use it for dimensional modeling and lookups: a categorization other tables join to, such as a set of segments with a color per value. **What you can do** * Define a **key** column and its attribute columns. * Reference it from other tables with **Dimension** columns, so their rows resolve to this dimension's values. * Edit its rows in the grid. Each dimension value shows a color, but colors are auto-assigned by row order from a fixed 8-color palette — they aren't user-set, aren't persisted (there's no color field on the table), and don't flow through to charts or dashboards. ## Create a dimension table On the [Tables](/features/tables) page, click **Create → Dimension Table**. Add your key and attribute columns with the **+ Add** column menu, then enter the dimension's values. A dimension table 'DemoDimensionTable' with a boolean column and a numeric column and a '+ Add' column menu listing SQL, Boolean, Date, Integer, Number, and Text. Create a dimension table.