This is the first of four movies (see below) The Field Effect Transistor made its entrance into industry in the shape of the JFET. Some time later, its younger cousin, the MOSFET, made a splash that continues to make it the centerpiece of digital electronic systems this day. I find it "natural" to explain the evolution from the JFET to the MOSFET using the simpler JFET mechanisms first. That is the approach: we begin with the JFET and then we move on to the MOSFET (in three aditional movies). I have also included a few tutorials, all listed below. I hope you find them useful.