Ans. The first generation computers were voluminous computers in which electronic valves were used. They were built by using vacuum tube. As the vacuum tubes were used as an electronic component, the computers were very large in size. ENIAC was the first computer of this category. Thus, the computer from ANIAC to IBM – 650 belongs to this generation. The data manipulation capacity of ENIAC was thirty times more than the previous computers vacuum tubes were replaced by the transistors. Transistors were very small in size and weighs as compared to vacuum tubes and consumed very low power.