Circuits

The word 'circuit' means a path something follows that goes back to where it started. In an electrical or electronic circuit, the thing following the path is of course electricity. Whatever work it does and whatever components it must go through on the way, the 'circuit' just means there is a complete path back to the starting point.

The word 'circuitry' means the components, and the connections between them, that make up the path. It's as simple as that.In a computer, this word 'circuit' shows up in a couple of places. Most of the components will be found soldered to a 'circuit board', also called a printed circuit board. This is a thin board of fiberglass, with the connections between components (called traces) printed right on the board in copper.

The components themselves are often something called an Integrated Circuit, abbreviated IC. To integrate means to combine things together, so an integrated circuit is one that combines many circuits into the same part. These are formed on a thin wafer or 'chip' of silicon, and you will sometimes hear an IC being called a 'chip'. This is also where we get the name 'Silicon Valley', for the area in Central California where many of them are made.



This chip of silicon is put into a case with metal legs, and tiny wires between the wafer and the legs connect those circuits with the outside world. There are now ICs containing millions of transistors and other components, all in a package that will fit in your palm with lots of room to spare.