While many of us love our machines, most of us have no clue how they work (as a computer engineering major, this pains me). The transistor is the most basic part of a computer: through transistors, we can create logic gates, and thus more complex digital logic structures. Placing these digital logic structures in a certain way allows us to create a general purpose microprocessor with its own instruction set. This video is a great explanation of how the transistor works, if you did not know how it worked before!
[video=youtube]https://www.youtube.com/watch?v=IcrBqCFLHIY[/video]
[video=youtube]https://www.youtube.com/watch?v=IcrBqCFLHIY[/video]