Bayesian Networks
Definition
A Bayesian network is a directed acyclic graph representing probabilistic relationships between variables using graph structure and conditional probability distributions.
What is a Bayesian network?
A Bayesian network is a directed acyclic graph whose nodes represent variables and whose edges represent conditional dependencies. Each variable has a probability distribution conditioned on its parent nodes.
How inference works
The graph provides a structured way to factor a joint probability distribution. If evidence about some variables is observed, probability rules can update beliefs about others. That makes Bayesian networks useful for diagnosis, prediction and reasoning when information is uncertain.
Why they matter in AI
AI does not operate only with deterministic rules. Bayesian networks became important because they make uncertainty explicit and mathematically tractable. Judea Pearl's work in the 1980s helped establish probabilistic graphical models as a major AI framework.
Related terms, defined
Reference guide and primary sources
Wikipedia is used here as a terminology and history reference guide. Current model versions, institutional statistics and product-specific claims are also linked to first-party or institutional sources because those details can change faster than encyclopedia articles.