Final answer:
The UNIVAC I was the first commercially marketed computer and was manufactured by the Remington Rand Corporation. This marked the start of the computer age, which led to the later dominance of mainframe computers and the introduction of personal computers.
Step-by-step explanation:
The first commercially marketed computer was the UNIVAC I, manufactured by the Remington Rand Corporation. This pivotal piece of computing history marks the beginning of an era, transitioning from room-filling, vacuum tube-operated machines to more reliable, compact systems. The UNIVAC I, a product of engineering and technical innovation, was delivered to the US Census Bureau in 1951, signaling the start of the computer revolution, which would later be dominated by companies like IBM with their mainframe computers and ultimately lead to the widespread development of personal computers, facilitated by groundbreaking innovations such as the microprocessor.