# Conditional Probability

> Source: https://sukruyusufkaya.com/en/glossary/kosullu-olasilik
> Updated: 2026-05-13T21:00:58.735Z
> Type: glossary
> Category: matematik-istatistik-optimizasyon
**TLDR:** A concept that measures how likely an event is given that another event has already occurred.

<p>Conditional probability allows us to evaluate uncertainty within context. Instead of asking how likely an event is by itself, we ask how likely it is given that some other information is already known. This is critical in real-world decision making because events are often not independent. Disease diagnosis, spam detection, credit risk assessment, and Bayesian learning all rely on conditional probability. In short, it provides the mathematical answer to the question: “How should our belief change when new information arrives?”</p>