Osquery is an open source tool that allows users to perform SQL queries on their system to retrieve information. It supports various platforms and makes it easy to get details about the system. Osquery consists of Osqueryi, Osqueryd, and Osqueryctl components. Basic queries can be run in user context mode to view system information, configuration, and tables. Osqueryd runs in daemon mode and can be configured using packs and decorators to monitor specific events and files. Osqueryctl is used to control the Osquery daemon process.