An integrated circuit is an electronic circuit on a flat piece of semiconductor material. ICs are a cheap way to manufacture circuits in a small package. They are often black and have metal pins to solder them to a PCB. ICs are used in nearly all electronic devices because of their low cost and high performance.
IC pinout diagramsIC pinout
There are many different ICs, all with their own function. Each of these ICs has a different pin configuration, which can be found in the pinout diagram. ICs have a notch to indicate where the first pin is. Here is an example of the 4017 IC.