Open-Source Intelligence (OSINT) refers to the collection and analysis of publicly available information from a variety of sources, including the Internet, media, academic journals, and government reports, to inform decision making and support strategic planning. It is a process of gathering, collating, and evaluating information that is available in the public domain and can be used to enhance situational awareness, support threat assessments, and inform a variety of other activities.
Source: Johnson, J. M. (2016). OSINT: A strategy for enhancing intelligence analysis. Journal of Strategic Security, 9(4), 1-22.