Before the invention of word processing and spreadsheet software, personal computers had little value in the mainstream business world. WordStar was used before the days of function keys and the mouse. It, instead, used a set of Ctrl and Alt key combinations to navigate and edit text documents.
The transistor, which essentially is a solid-state electronic switch, replaced the much less suitable vacuum tube. Because the transistor consumed significantly less power, a computer system built with transistors was much smaller, faster and more efficient than a computer system built with vacuum tubes.