Help: Clarify target_sources PRIVATE/PUBLIC/INTERFACE scopes
diff --git a/Help/command/target_sources.rst b/Help/command/target_sources.rst
index 856d869..653b8d7 100644
--- a/Help/command/target_sources.rst
+++ b/Help/command/target_sources.rst
@@ -11,19 +11,21 @@
<INTERFACE|PUBLIC|PRIVATE> [items1...]
[<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])
-Specifies sources to use when compiling a given target. Relative
-source file paths are interpreted as being relative to the current
+Specifies sources to use when building a target and/or its dependents.
+Relative source file paths are interpreted as being relative to the current
source directory (i.e. :variable:`CMAKE_CURRENT_SOURCE_DIR`). The
named ``<target>`` must have been created by a command such as
:command:`add_executable` or :command:`add_library` and must not be an
:ref:`ALIAS target <Alias Targets>`.
The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
-specify the scope of the following arguments. ``PRIVATE`` and ``PUBLIC``
+specify the scope of the items following them. ``PRIVATE`` and ``PUBLIC``
items will populate the :prop_tgt:`SOURCES` property of
-``<target>``. ``PUBLIC`` and ``INTERFACE`` items will populate the
-:prop_tgt:`INTERFACE_SOURCES` property of ``<target>``.
-(:ref:`IMPORTED targets <Imported Targets>` only support ``INTERFACE`` items.)
+``<target>``, which are used when building the target itself.
+``PUBLIC`` and ``INTERFACE`` items will populate the
+:prop_tgt:`INTERFACE_SOURCES` property of ``<target>``, which are used
+when building dependents. (:ref:`IMPORTED targets <Imported Targets>`
+only support ``INTERFACE`` items because they are not build targets.)
The following arguments specify sources. Repeated calls for the same
``<target>`` append items in the order called.
