diff --git a/docs/data/common-concepts/custom-components/custom-components.md b/docs/data/common-concepts/custom-components/custom-components.md
index 94a066e36bb5..fdd9669e0d11 100644
--- a/docs/data/common-concepts/custom-components/custom-components.md
+++ b/docs/data/common-concepts/custom-components/custom-components.md
@@ -4,7 +4,15 @@
 
 ## What is a slot?
 
-A slot is a part of a component that can be overridden and/or customized.
+A slot is a part of a component that can be [overridden](/x/common-concepts/custom-components/#how-to-override-a-slot) and/or [customized](/custom-components/#how-to-customize-a-slot).
+
+Some of those slots allow you to provide your own UI primitives to the MUI X components.
+This is the role of all the `baseXXX` component on the `DataGrid` component (`baseButton`, `baseSelect`, ...).
+These slots receive props that should be as generic as possible so that it is easy to interface any other design system.
+
+Other slots allow you to override parts of the MUI X UI components with a custom UI built specifically for this component.
+This is the role of slots like `calendarHeader` on the `DateCalendar` component or `item` on the `RichTreeView` component.
+These slots receive props specific to this part of the UI and will most likely not be re-use throughout your application.
 
 ## Basic usage