What are transistors?

Transistors are the smallest unit of computing possible, used practically thus far. Harnessing the physical properties of certain metallic-like rocks, we are able to create very small switches which are able to remember their state. Just like how a regular mechanical switch is able to remain on or off until a person comes along to press it to change its shape, transistors are essentially electrical switches, solely operating on either current or voltage.

By fabricating these switches into sizes smaller then the width of a human hair, we are able to pack an insane number of them into a vary small volume of area. The proliferation of handheld technology from the late 80s to now was in part possible due to massive leaps in shrinking transistors sizes from the sizes of light bulbs, to close to the sizes of molecules and atoms.

These small devices are what makes the spread of electronic & computers possible on massive scale. While the technology of fabricating such devices are a tightly kept secret, it has been industrialized to the point where it is massively produced on large scales. Such devices are used from the manufacture of car doors, to the smartphones & processors which powers our communication satellites.

By cleverly arranging these switches which are able to 'remember' its states depending on the current or voltage passed through them, we are able to come up with logic circuits, which in turn are able to build upon more complex computation units like calculators (Algorithmic Processing Units) and the Central Processing Unit (CPU) which is able to run computations on programs passed and data stored in memory & registers.

With that brief introduction on transistors, these units are what makes the technological age of today's modern era possible.