To design, install, and configure a cloud, cloud administrators must understand the logical architecture. OpenStack modules are one of the following types: Daemon. Runs as a daemon. On Linux platforms, a daemon is usually installed as a service. Script. Installs and tests of a virtual environment. For example, the run_tests.sh script installs and optionally tests a virtual environment for a service. Command-line interface (CLI). Enables users to submit API calls to OpenStack services through easy-to-use commands. The following diagram shows the most common, but not the only, architecture for an OpenStack cloud:

As in , end users can interact through the dashboard, CLIs, and APIs. All services authenticate through a common Identity Service and individual services interact with each other through public APIs, except where privileged administrator commands are necessary.