diff --git a/images/layers.png b/images/layers.png
new file mode 100644
index 0000000..4df9160
--- /dev/null
+++ b/images/layers.png
Binary files differ
diff --git a/navigate.md b/navigate.md
index 0a6db80..2acf404 100644
--- a/navigate.md
+++ b/navigate.md
@@ -1,5 +1,37 @@
 # Navigating CORD
 
+## Assembled in Layers
+
+A given instance of CORD is constructed from a set of disaggregated
+components. This assembly is done according to the general pattern
+shown in the following conceptual diagram.
+
+![Layers](images/layers.png)
+
+The three layers are:
+
+* **Platform:** The bottom-most layer consists of ONOS, XOS,
+  Kafka, and collection of Logging and Monitoring micro-services,
+  all running on a Kubernetes foundation (not shown). This is the
+  starting point for all configurations of CORD.
+
+* **Profile:** The middle layer typically consists of a set of
+  services (e.g., access services, VNFs, other cloud services). These
+  components run on the underlying platform, and includes both
+  abstract services on-boarded into XOS and SDN control apps running
+  on ONOS.
+
+* **Workflows:** The top-most layer consists of one or more
+  workflows, each of which defines the business logic and state
+  machine for one of the access technologies included in the
+  profile. A workflow augments/parameterizes a profile for the target
+  deployment environment; it's not a software layer, per se.
+
+The diagram also shows a hardware bill-of-materials, which must be
+defined for a given POD.
+
+## Operationalized in Stages
+
 Understanding the relationship between installing, operating, and developing
 CORD—and the corresponding toolsets and specification files used by
 each stage—is helpful in navigating CORD.
diff --git a/overview.md b/overview.md
index c6a67da..ce3e3aa 100644
--- a/overview.md
+++ b/overview.md
@@ -1,7 +1,14 @@
 # CORD Guide
 
-This is a curated set of guides that describe how to install, operate, test,
-and develop [CORD](https://opencord.org).
+This is a curated set of documents that describe how to install, operate, test,
+and develop [CORD](https://www.opennetworking.org/cord/).
+The material is organized in two parts:
+
+* *Guides:* Outlines the process of installing, operating, testing and
+   developing for CORD as a whole.
+
+* *References:* Definitions and specifications about individual
+   components that make up CORD.
 
 CORD is a community-based open source project. In addition to this guide, you
 can find information about this community, its projects, and its governance on
@@ -9,9 +16,9 @@
 and design notes that have shaped [CORD's
 architecture](https://wiki.opencord.org/display/CORD/Documentation).
 
-## Navigating the Guide
+## Navigating the Guides
 
-The guide is organized around the major stages in the lifecycle of CORD:
+The guides are organized around the major stages in the lifecycle of CORD:
 
 * [Installation](README.md): Installing (and later upgrading) CORD.
 * [Operations](operating_cord/operating_cord.md): Operating an already
@@ -24,7 +31,24 @@
 These are all fairly obvious. What's less obvious is the relationship among
 these stages, which is helpful in [Navigating CORD](navigate.md).
 
-## Making Changes to the Guide
+## Navigating the References
+
+CORD is built from components and the aggregation of components into a
+coherent solution. The References are organized accordingly:
+
+* [Profile Reference](profiles/intro.md): Installation and
+  configuation details for specific solutions built using CORD
+  components.
+* [Service Reference](operating_cord/services.md): Configuration
+   (TOSCA) and modeling (xproto) definitions for individual CORD
+   components.
+* [Helm Refernce](charts/helm.md): Helm charts used to install
+   individual CORD components.
+
+For more information on the relationship between Profiles and
+Services, see [Navigating CORD](navigate.md).
+
+## Making Changes to this Document
 
 The [http://guide.opencord.org](http://guide.opencord.org) website is built
 using the [GitBook Toolchain](https://toolchain.gitbook.com/), with the
diff --git a/quickstart.md b/quickstart.md
index bf1354d..544963d 100644
--- a/quickstart.md
+++ b/quickstart.md
@@ -1,13 +1,14 @@
 # Quick Start
 
 This section walks you through an example installation sequence on two
-different platforms. If you'd prefer to understand the installation
-process in more depth, including the full range of deployment options,
-you might start with the [Installation Guide](README.md) instead.
+different Unix-based platforms. This is just a surface introduction to
+CORD. If you'd prefer to understand the installation process in more
+depth, including the full range of deployment options, you should
+start with the [Installation Guide](README.md) instead.
 
-This Quick Start describes how to install the R-CORD profile, plus a
-`SimpleExampleService`, on a single machine. Once you complete these
-steps, you might be interested in jumping ahead to the
+This Quick Start describes how to install a subset of the CORD
+platform, plus a `SimpleExampleService`, on a single machine. Once you
+complete these steps, you might be interested in jumping ahead to the
 [SimpleExampleService Tutorial](simpleexampleservice/simple-example-service.md)
 to learn more about the make-up of a CORD service. Another option
 would be to explore CORD's [operational interfaces](operating_cord/general.md).