What are first generation computers?

In first generation computers (1945-1956) the operating instructions or programs were specifically built for the task for which the computer was manufactured. They relied on machine language to perform operations, and they could only solve one problem at a time. The Input was based punched cads and paper tape, and the output was displaced on printouts. It was very difficult to program these computers, and they were difficult to repair when something went wrong. Data was stored in vacuum tubes and magnetic drums. First generation computers were often enormous, taking up entire rooms. They were very expensive to operate, and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions.