Re-work the README introduction

README.md

@@ -1,8 +1,14 @@
 # Pulp 3 Containers
 
-- [Multi-Process Images](multi-process-images) - A single image that runs [Pulp](https://github.com/pulp/pulpcore) or [Ansible Galaxy](https://github.com/ansible/galaxy_ng), as well as its [third-party services](#third-party-services),
-in one single Docker/Podman container.
-- [Single-Process Images](single-process-images) - These images are currently used by [pulp operator](https://docs.pulpproject.org/pulp_operator/), but they can be used in docker-compose or podman-compose. You can find a compose example [here](https://github.com/pulp/pulp-oci-images/tree/latest/images/compose).
+The [pulp-oci-images](https://github.com/pulp/pulp-oci-images) repository is used to provide container images for running Pulp.
+These images represent one of several officially supported [Pulp installation methods](https://docs.pulpproject.org/pulpcore/installation/instructions.html).
+The available images can be divided into two types:
+
+- [Multi-Process Images](multi-process-images) - Images for running a [Pulp](https://github.com/pulp/pulpcore) or [Ansible Galaxy](https://github.com/ansible/galaxy_ng), as well as its [third-party services](#third-party-services),
+in a single Docker/Podman container.
+- [Single-Process Images](single-process-images) - Images containing a single Pulp service each, which collectively make up a Pulp instance. They can be used via docker-compose or podman-compose, example [here](https://github.com/pulp/pulp-oci-images/tree/latest/images/compose). These images are also used by [pulp operator](https://docs.pulpproject.org/pulp_operator/).
+
+Note that OCI stands for "Open Container Initiative", see [here](https://opencontainers.org/).
 
 ## Available Images