Any 1 knows how about diodes?

Question

Any 1 knows how about diodes?

Answer 1

Yes, I know about them. There's many kinds - small signal, power, LEDs, laser, etc. They all share the same thing in common: they have a "rectifying" action where they pass current in one direction and not the other.

Almost all diodes made today are "solid state", meaning they're made from semiconductor materials. Before this, diodes were made a variety of ways, including vacuum tubes, selenium rectifiers, "cat whisker" (point-contact) junctions and so forth. Link below with more info.