During the 1940s and 1950s, vacuum tubes were the primary electronic components used in computers and other electronic devices. These tubes were large, consumed a lot of power, and generated significant heat. Mainframes, which were large, powerful computers designed for high-volume data processing, relied on these vacuum tubes for their operation.
The development of transistors and integrated circuits in the late 1950s and 1960s led to smaller, more energy-efficient computers, marking the end of vacuum tube dominance and the beginning of modern computing.