Statistics, construed broadly, is the study of uncertainty: how to measure it (using ideas and methods in probability theory), and what to do about it (using concepts from statistical inference and decision theory). Statistics is a key foundational discipline for data science, and has applications in a wide variety of fields. You can learn more about Statistics by visiting the the American Statistical Association.
At the graduate level, the department offers both an M.S. and a Ph.D. in Statistical Science, as well as a Designated Emphasis in Statistics, which is available to all graduate students at UCSC. At the undergraduate level, the department offers a Minor in Statistics and a 4+1 contiguous pathway into its M.S. for students from any quantitative major who satisfy the course requirements. The minor complements any major in the Baskin School of Engineering, as well as many of the majors in the Social, Physical, and Biological Sciences.