A vacuum tube also called a electron tubes is a sealed glass or metal-ceramic enclosure used in electronic circuitry to control the flow of electrons between the metal electrodes sealed inside the tubes. The air inside the tubes is removed by a vacuum. Vacuum tubes are used for: amplification of a weak current, rectification of an alternating current to direct current (AC to DC), generation of oscillating radio-frequency (RF) power for radio and radar, and more.
According to PV Scientific Instruments, "The earliest forms of such tubes appeared in the late 17th century. However, it was not until the 1850s that sufficient technology existed to produce sophisticated versions of such tubes. This technology included efficient vacuum pumps, advanced glassblowing techniques, and the Ruhmkorff induction coil."
In 1875, American, G.R. Carey invented the phototube.
In 1878, Englishman Sir William Crookes invented the 'Crookes tube', an early prototype of cathode-ray tube.