BBN

BBN is an acronym with several meanings across science and technology.

- Bayesian belief network: A probabilistic graphical model representing a set of variables and their conditional dependencies via a directed acyclic graph. Each node is a random variable; edges encode conditional dependencies. They support probabilistic inference, decision making, and learning under uncertainty. Applications include medical diagnosis, risk assessment, forecasting, and machine learning.

- Bolt, Beranek and Newman (BBN): A U.S. technology company founded in 1948 in Cambridge, Massachusetts. BBN became a prominent contractor in computer networking and a pioneer in the ARPANET project, designing and deploying some of the earliest network hardware and protocols, including the Interface Message Processor. The firm later evolved into BBN Technologies, focusing on research and development for defense, government, and commercial clients. In 2009, BBN Technologies was acquired by Raytheon Company (now part of Raytheon Technologies), and continues to operate as a research-focused subsidiary.