Also, transistors can be miniaturized. In an integrated circuit , millions can be packed into a piece of silicon the size of a fingernail. Voltage is just one part of the power equation, but the other part, current, also has to be much higher in the vacuum tube because the tube needs to warm up. Generating heat takes lots of power. Not only don't transistors waste time warming up when the circuit is first powered up, but they can also switch on and off much faster than a vacuum tube.
Vacuum tubes are more like light bulbs with wires inside a bottle that's had all the air sucked out.
This is especially important in airplanes, cars, and anything else shakes, rattles, and rolls. Semiconductors are elements that form crystals along which electrons can either travel easily or hardly at all, depending on whether extra electrons are available or some of electrons are missing. Just a few of these electrons one way or the other can have a big impact on how much electricity can flow through. If these few electrons are a signal, then the large number of electrons that can or cannot flow because of that signal is an amplification of that signal. This amplifier is a basic building block of everything electronic, from radios to computers.