Single-cell genomics is a catch phrase for numerous new technologies and methods that allow for probing cells at genome scale. I will explain what this means and describe some examples that illustrate the excitement in this new domain. While single-cell genomics technologies draw on methods from a variety of disciplines such asf biology, chemistry and engineering, the interpretation of the data they generate requires concepts and tools from statistics, computer science and mathematics. I will explain some of the connections with a view towards highlighting interesting solved and unsolved problems in the field.