ref-manual: terms.rst: add SBOM and SPDX terms

(From yocto-docs rev: 2c53ac40e99a7957736276c5bf925b3f81544aa5)

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/terms.rst

@@ -321,6 +321,23 @@ universal, the list includes them just in case:
       :term:`build host<Build Host>` and other components, that can
       work on specific hardware.
 
+   :term:`SBOM`
+      This term means *Software Bill of Materials*. When you distribute
+      software, it offers a description of all the components you used,
+      their corresponding licenses, their dependencies, the changes that were
+      applied and the known vulnerabilities that were fixed.
+
+      This can be used by the recipients of the software to assess
+      their exposure to license compliance and security vulnerability issues.
+
+      See the `Software Supply Chain <https://en.wikipedia.org/wiki/Software_supply_chain>`__
+      article on Wikipedia for more details.
+
+      The OpenEmbedded Build System can generate such documentation for your
+      project, in :term:`SPDX` format, based on all the metadata it used to
+      build the software images. See the ":ref:`dev-manual/common-tasks:creating
+      a software bill of materials`" section of the Development Tasks manual.
+
    :term:`Source Directory`
      This term refers to the directory structure
      created as a result of creating a local copy of the ``poky`` Git
@@ -381,6 +398,15 @@ universal, the list includes them just in case:
      ":ref:`overview-manual/development-environment:repositories, tags, and branches`"
      section in the Yocto Project Overview and Concepts Manual.
 
+   :term:`SPDX`
+      This term means *Software Package Data Exchange*, and is used as a open
+      standard for providing a *Software Bill of Materials* (:term:`SBOM`).
+      This standard is developed through a `Linux Foundation project
+      <https://spdx.dev/>`__ and is used by the OpenEmbedded Build System to
+      provide an :term:`SBOM` associated to each a software image.
+
+      For details, see Wikipedia's `SPDX page <https://en.wikipedia.org/wiki/Software_Package_Data_Exchange>`__.
+
    :term:`Sysroot`
       When cross-compiling, the target file system may be differently laid
       out and contain different things compared to the host system. The concept