Dimensions are the columns in your table. They are the "attributes" of your data. For example, user_id in your users table is a dimension.
For a dimension to appear in Lightdash, you just need to declare it in your dbt model's YAML file.
Column descriptions in your YAML file are automatically pulled into Lightdash and you can spot them if you hover over the dimension name 👀
Dimension types are automatically pulled from your tables schemas in Lightdash. We currently support these dimension types: