What Is Open Source Intelligence (OSINT)?

This article explains the fundamentals of Open Source Intelligence (OSINT)—what it is, where it comes from (surface, deep, and dark web), its evolution, and how it is used in cybersecurity for ethical hacking, threat identification, and risk mitigation. It contrasts passive vs. active collection, highlights common tools and techniques (e.g., TIPs, machine learning, Google dorks, Spiderfoot, Recon-ng), and underscores the dual-use nature of OSINT, the risks of information overload, and the need for clear strategy, legal compliance, and ethical practices.