Explore the fundamentals of statistics and data analysis in this lecture from the International Centre for Theoretical Sciences' program on "Cosmology - The Next Decade". Delve into key concepts including probability, joint probability, conditional probability, joint PDF, independence, Bayes Theorem, data conditioning, and modeling. Learn how these statistical tools are applied to cosmological research, helping scientists unravel mysteries like dark matter and dark energy. Gain insights into the challenges and opportunities in modern cosmology as the field prepares for the next generation of experiments and observational data.