Joins let you to connect different models to each other so that you can explore more than one model at the same time in Lightdash and see how different parts of your data relate to each other.
Joins are defined at the same level as your model parameters in your YAML file.
All joins are defined as
LEFT OUTER joins.
When you open Lightdash, your joined models' dimensions and metrics will appear below the ones in your selected model.