Computer science (also called computing science, and often abbreviated CS) is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems. Computer scientists invent algorithmic processes that create, describe, and transform information and formulate suitable abstractions to model complex systems.
As a discipline, computer science spans a range of topics from theoretical studies of algorithms and the limits of computation to the practical issues of implementing computing systems in hardware and software.
While some computer science questions are on-topic for Stack Overflow, many of the more theoretical questions or questions that do not apply to programming are off-topic. You can ask these types of questions on the Computer Science Stack Exchange.