# Anatomy This page details the core concepts you need to know to use Fleet. ## Fleet UI Fleet UI is the GUI (graphical user interface) used to control Fleet. [Learn more](https://youtu.be/1VNvg3_drow?si=SWyQSEQMoHUYDZ8C). ## Fleetctl Fleetctl (pronounced “fleet control”) is a CLI (command line interface) tool for managing Fleet from the command line. [Docs](https://fleetdm.com/docs/using-fleet/fleetctl-cli). ## Fleetd Fleetd is a bundle of agents provided by Fleet to gather information about your devices. Fleetd includes: - **Osquery:** an open-source tool for gathering information about the state of any device that the osquery agent has been installed on. [Learn more](https://www.osquery.io/). - **Orbit:** an osquery version and configuration manager, built by Fleet. [Learn more](https://github.com/fleetdm/fleet/blob/main/orbit/README.md) - **Fleetd Chrome extension:** enrolls ChromeOS devices in Fleet. [Docs](https://github.com/fleetdm/fleet/blob/main/ee/fleetd-chrome/README.md). ## Fleet Desktop Fleet Desktop is a menu bar icon that gives end users visibility into the security and status of their machine. [Docs](https://fleetdm.com/docs/using-fleet/fleet-desktop). ## Host A host is a computer, server, or other endpoint. Fleet gathers information from Fleet's agent (fleetd) installed on each of your hosts. [Docs](https://fleetdm.com/docs/using-fleet/adding-hosts). ## Fleet A fleet is a group of hosts. Organize hosts into fleets to apply queries, policies, scripts, and other configurations tailored to their specific risk and compliance requirements. [Read the guide](https://fleetdm.com/guides/fleets). ## Report A report in Fleet is a saved question about your devices. It’s powered by [osquery](#fleetd) with logic written in SQL, which lets you collect specific data from hosts. Use reports to monitor your fleet, verify settings, and spot security issues. [Docs](https://fleetdm.com/docs/using-fleet/fleet-ui). ## Policy A policy is a specific “yes” or “no” question. Use policies to manage security compliance in your organization. [Read the guide](https://fleetdm.com/securing/what-are-fleet-policies). ## Host vitals Fleet's built-in queries for collecting and storing important device information. ## Software Software in Fleet refers to the following: - **Software library:** a collection of Fleet-maintained apps, VPP, and custom install packages that can be installed on your hosts. [See available software](https://fleetdm.com/app-library). - **Software inventory** an inventory of each host’s installed software, including information about detected vulnerabilities (CVEs).