This lecture introduces the three main domains of computer science: scientific computing, process automation, and data management. Scientific computing involves simulating complex systems and requires high computational power. Process automation focuses on embedded systems controlling various processes, from industrial chains to household appliances. Data management deals with handling and processing large amounts of information efficiently and securely, used in banking systems, e-commerce, and more. The lecture explores the applications and requirements of each domain, emphasizing the crucial role of computer science in various sectors.