Why did time-sharing systems become important in the 1960s?

In the 1960s, time-sharing systems became essential for two primary reasons: the need to maximize the utility of expensive computing hardware and the desire to shift from inefficient batch processing to interactive computing.12

During this era, computers were costly, and the standard "batch processing" method—where users submitted decks of punched cards and waited hours for results—was highly inefficient. Because the central processing unit (CPU) operated significantly faster than peripheral equipment, it often sat idle. Time-sharing allowed multiple users to interact with the system simultaneously, as the CPU could solve discrete problems for different users during the input/output process, making the system appear to provide instantaneous feedback.21

This shift was driven by pioneers like J.C.R. Licklider and supported by ARPA, leading to landmark developments such as the Compatible Time-Sharing System (CTSS) and Project MAC. These innovations necessitated new operating systems, such as Multics and eventually UNIX, which fundamentally changed how users engaged with technology.2