diff --git a/docs/global_substitutions.txt b/docs/global_substitutions.txt
index 3e74ba7..8011fc6 100644
--- a/docs/global_substitutions.txt
+++ b/docs/global_substitutions.txt
@@ -11,6 +11,7 @@
 .. |SEMVER| replace:: `Semantic Versioning`_
 .. |PSA| replace:: :term:`PSA`
 .. |FF-A| replace:: :term:`FF-A`
+.. |TRUSTZONE| replace:: :term:`TrustZone`
 
 .. _`TS Mailing List`: https://lists.trustedfirmware.org/mailman3/lists/trusted-services.lists.trustedfirmware.org/
 .. _`TS repository`: https://review.trustedfirmware.org/admin/repos/TS/trusted-services
diff --git a/docs/project/glossary.rst b/docs/project/glossary.rst
index 74356c0..55b17f7 100644
--- a/docs/project/glossary.rst
+++ b/docs/project/glossary.rst
@@ -29,16 +29,64 @@
     FF-A
         `Firmware Framework for A`_
 
+    TEE
+        Trusted Execution Environment. An SPE implemented using TrustZone.
+
+    TrustZone
+        Hardware assisted isolation technology built into arm CPUs. See `TrustZone for Cortex-A`_.
+
+    SPE
+        See :term:`Secure Processing Environment`.
+
+    Secure Processing Environment
+        An isolated environment to execute software images backed by a specific set of hardware and arm architecture
+        features. The aim of isolation os to protect sensitive workloads and their assets.
+
+    SP
+        see :term:`Secure Partition`
+
+    Secure Partition
+        Secure Partition is a compartment to execute a software image isolated from other images. Isolation can be logical
+        or physical based on if physical address range isolation is involved or not. See :term:`Physical SP` and :term:`Logical SP`.
+
+        An SP may host a single or multiple services.
+
+    Physical SP
+        A Secure Partition which executes a software image in and isolated physical address space.
+
+    Logical SP
+        A Secure Partition which executes a software image isolated buy without physical address space isolation.
+
+    SPM
+        See :term:`Secure Partition Manager`.
+
+    Secure Partition Manager
+        A component responsible for creating and managing the physical isolation boundary of an :term:`SP` in the SWd. It
+        is built from two sub-components the :term:`Secure Partition Manager Dispatcher` and the
+        :term:`Secure Partition Manager Core`.
+
+    Secure Partition Manager Dispatcher
+        The SPM component responsible for SPMC initialization boot-time, and forwarding FF-A calls run-time between SPs
+        and between SPs and the SPMC.
+
+    Secure Partition Manager Core
+        A component responsible for SP initialization and isolation at boot-time, inter partition isolation at run-time,
+        inter-partition communication at run-time.
+
+    Secure Enclave
+        An isolated hardware subsystem focusing on security related operations. The subsystem may include hardware
+        peripherals and one or more processing elements. As an example see the `Arm SSE-700`_ subsystem.
 
 --------------
 
-.. _`Arm Glossary`: https://developer.arm.com/support/arm-glossary
+.. _`Arm Glossary`: https://developer.arm.com/documentation/aeg0014
 .. _`Linux Coding Style`: https://www.kernel.org/doc/html/v4.10/process/coding-style.html
 .. _`Arm C language extensions`: https://developer.arm.com/documentation/101028/0012/?lang=en
 .. _`Platforn Security Arhitecture`:  https://developer.arm.com/architectures/security-architectures/platform-security-architecture
 .. _`Firmware Framework for A`: https://developer.arm.com/docs/den0077/latest
+.. _`TrustZone for Cortex-A`: https://www.arm.com/technologies/trustzone-for-cortex-a
+.. _`Arm SSE-700`: https://developer.arm.com/documentation/101418/0100/Overview/About-SSE-700
 
-
-*Copyright (c) 2020-2021, Arm Limited and Contributors. All rights reserved.*
+*Copyright (c) 2020-2022, Arm Limited and Contributors. All rights reserved.*
 
 SPDX-License-Identifier: BSD-3-Clause