diff --git a/docs/environments/index.rst b/docs/environments/index.rst
index 18948ea..adb9008 100644
--- a/docs/environments/index.rst
+++ b/docs/environments/index.rst
@@ -1,9 +1,15 @@
 Environments
 ============
 
+Depending on Arm architecture and SoC capabilities, there may be different options for
+implementing hardware-backed isolation for protecting security sensitive workloads. The
+Trusted Services project decouples service related components from any particular
+environment, enabling services to be deployed in different environments. This section
+provides information about supported secure processing environments.
+
 .. toctree::
     :maxdepth: 1
-    :caption: Contents:
+    :caption: Supported Environments:
 
     secure-partitions/index
 
diff --git a/docs/environments/secure-partitions/ff-a/index.rst b/docs/environments/secure-partitions/ff-a/index.rst
new file mode 100644
index 0000000..5c7dc03
--- /dev/null
+++ b/docs/environments/secure-partitions/ff-a/index.rst
@@ -0,0 +1,16 @@
+Firmware Framework for Armv8-A
+==============================
+
+|FF-A| is a standard which *"describes interfaces that standardize communication between the various software images. This
+includes communication between images in the Secure world and Normal world."*
+
+Trusted Services is the home of the FF-A S-EL0 Secure Partitions implementing PSA functionality. The component :ref:`libsp`
+captures helpful abstractions to allow easy FF-A compliant S-EL0 SP development. S-EL0 SPs are SPMC agonistic and can be used
+with an SPMC running in any higher secure exception level (S-EL1 - S-EL3). Currently the solution is tested with an SPMC
+running at S-SEL1 integrated into OP-TEE OS.
+
+--------------
+
+*Copyright (c) 2021-2022, Arm Limited and Contributors. All rights reserved.*
+
+SPDX-License-Identifier: BSD-3-Clause
diff --git a/docs/environments/secure-partitions/index.rst b/docs/environments/secure-partitions/index.rst
index 9ab70d1..d57b103 100644
--- a/docs/environments/secure-partitions/index.rst
+++ b/docs/environments/secure-partitions/index.rst
@@ -1,16 +1,40 @@
 Secure Partitions
 =================
 
+:term:`Secure Partitions<Secure Partition>` are defined by the :term:`FF-A` standard
+
+Secure partitions are isolated processing environments managed by a Secure Partition Manager (SPM).
+An SPM performs the role of hypervisor for the Arm Secure state and is responsible for managing
+SP initialization, memory management and messaging. The Arm Firmware Framework for A-Profile (FF-A)
+specification (`FF-A Specification`_) defines the set of firmware features that enable the use of
+secure partitions for protecting sensitive workloads.
+
+The Armv8.4 architecture introduces the virtualization extension in the Secure state. For silicon
+based on Armv8.4 (or above) that implement the Secure-EL2 extension, the `Hafnium Project`_
+provides a reference SPM implementation. For pre-Arm8.4 silicon, the `OP-TEE Project`_ provides
+an alternative reference SPM implementation.
+
+Within the Trusted Services, the environments realized by the two reference SPM implementations
+are named as follows:
+
+    * *hfsp* - for service deployment under Hafnium
+    * *opteesp* - for service deployment under OP-TEE
+
 .. toctree::
     :maxdepth: 1
     :caption: Contents:
 
+    ff-a/index
+    spm/optee/index
+    spm/hafnium/index
     libsp
-    userspace-programs-on-fvp
-    opteesp-deployment-guide
 
 --------------
 
+.. _`FF-A Specification`: https://developer.arm.com/documentation/den0077/latest
+.. _`Hafnium Project`: https://www.trustedfirmware.org/projects/hafnium/
+.. _`OP-TEE Project`: https://www.trustedfirmware.org/projects/op-tee/
+
 *Copyright (c) 2020-2022, Arm Limited and Contributors. All rights reserved.*
 
 SPDX-License-Identifier: BSD-3-Clause
diff --git a/docs/environments/secure-partitions/spm/hafnium/index.rst b/docs/environments/secure-partitions/spm/hafnium/index.rst
new file mode 100644
index 0000000..88cbbcc
--- /dev/null
+++ b/docs/environments/secure-partitions/spm/hafnium/index.rst
@@ -0,0 +1,12 @@
+S-EL1 Secure Partitions under Hafnium
+=====================================
+
+.. toctree::
+    :maxdepth: 1
+    :caption: Contents:
+
+--------------
+
+*Copyright (c) 2022, Arm Limited and Contributors. All rights reserved.*
+
+SPDX-License-Identifier: BSD-3-Clause
diff --git a/docs/environments/secure-partitions/spm/optee/index.rst b/docs/environments/secure-partitions/spm/optee/index.rst
new file mode 100644
index 0000000..2149880
--- /dev/null
+++ b/docs/environments/secure-partitions/spm/optee/index.rst
@@ -0,0 +1,15 @@
+S-EL0 Secure Partitions under OP-TEE
+====================================
+
+.. toctree::
+    :maxdepth: 1
+    :caption: Contents:
+
+    userspace-programs-on-fvp
+    opteesp-deployment-guide
+
+--------------
+
+*Copyright (c) 2022, Arm Limited and Contributors. All rights reserved.*
+
+SPDX-License-Identifier: BSD-3-Clause
diff --git a/docs/environments/secure-partitions/opteesp-deployment-guide.rst b/docs/environments/secure-partitions/spm/optee/opteesp-deployment-guide.rst
similarity index 100%
rename from docs/environments/secure-partitions/opteesp-deployment-guide.rst
rename to docs/environments/secure-partitions/spm/optee/opteesp-deployment-guide.rst
diff --git a/docs/environments/secure-partitions/userspace-programs-on-fvp.rst b/docs/environments/secure-partitions/spm/optee/userspace-programs-on-fvp.rst
similarity index 100%
rename from docs/environments/secure-partitions/userspace-programs-on-fvp.rst
rename to docs/environments/secure-partitions/spm/optee/userspace-programs-on-fvp.rst