Which innovation is credited with making personal computers mainstream?

The development of the microprocessor is widely recognized as the key innovation that propelled personal computers into the mainstream. The microprocessor, a compact integrated circuit that contains the core functions of a computer's central processing unit (CPU), enabled the creation of smaller, more affordable, and accessible computing devices. Prior to the microprocessor's widespread adoption in the early 1970s, computers were primarily large, expensive machines used by businesses and institutions.

With the arrival of microprocessors, it became feasible to design personal computers that could fit on a desk, making technology accessible to individual users and small businesses. This pivotal shift not only allowed for the proliferation of personal computers in homes and offices but also spurred significant advancements in software and peripheral technology, further embedding computers into everyday life.