To design, deploy, and configure OpenStack, administrators must understand the logical architecture. OpenStack modules are one of the following types: Daemon. Runs as a background process. On Linux platforms, a daemon is usually installed as a service. Script. Installs a virtual environment and runs tests. For example, the run_tests.sh script installs a virtual environment and runs unit tests on 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.