In general, computer science was the field of science relating to the theory, algorithms, design, and architecture of information processing systems. These concepts were the foundation of all Starfleet computer and sensory systems. It encompassed the fields of cybernetics and robotics.
In 2266, the multitronic unit was considered a revolution in computer science. (TOS: "The Ultimate Computer")
In 2364, as Lieutenant Commander Data began his exposition on how he had discovered checksum discrepancies between the main computer logs of the USS Stargazer and the personal logs of Captain Jean-Luc Picard, Commander William T. Riker cut him off by saying, "I don't want a computer science lesson, Data." (TNG: "The Battle")
Kurt Mandl held advanced degrees in computer science as well as artificial intelligence. (TNG: "Home Soil")