Open source intelligence (OSINT) involves gathering information about an organization from publicly available online sources to understand its operations and identify potential vulnerabilities. This includes researching the organization's products, acquisitions, investors and supply chain, as well as technical details like domains, digital assets, IP addresses and technology stack. It also involves analyzing employee information from sources like email addresses, coding platforms and content sharing under usernames, looking for password reuse risks. Adopting proper operational security (OpSec) measures can help organizations defend against threats identified through OSINT analysis.