diff --git a/documentation/sdk-manual/intro.rst b/documentation/sdk-manual/intro.rst
index b78248d54..c8fa8d619 100644
--- a/documentation/sdk-manual/intro.rst
+++ b/documentation/sdk-manual/intro.rst
@@ -123,6 +123,25 @@ sysroot is based on the target root filesystem image that is built by
 the OpenEmbedded build system and uses the same metadata configuration
 used to build the cross-toolchain.
 
+However, the extensible and standard SDKs :term:`sysroots <Sysroot>` differ in content:
+
+-  The standard SDK :term:`sysroot` only contains libraries and headers for the packages
+   --- and their dependencies --- found in the :term:`TOOLCHAIN_TARGET_TASK`
+   and :term:`TOOLCHAIN_HOST_TASK` definitions, for the target and host
+   :term:`sysroots <sysroot>` respectively.
+
+   See :doc:`/sdk-manual/appendix-obtain` to learn how to build it and
+   :doc:`/sdk-manual/appendix-customizing-standard` to learn how to customize
+   it.
+
+-  The extensible SDK :term:`sysroot` is completely managed by the :doc:`devtool
+   </ref-manual/devtool-reference>` command-line tool, and its content is the
+   same as the :term:`sysroot` of the image recipe for which the SDK was built.
+
+   See :doc:`/sdk-manual/appendix-obtain` to learn how to build it and
+   :doc:`/sdk-manual/appendix-customizing` to learn how to customize
+   it.
+
 The QEMU Emulator
 -----------------