In this chapter, we discuss what transients are and how important they are to engineering. We then look at the transients for the DC LR circuit with zero initial conditions and then extend the analysis to look at how the circuit responds when it has some initial conditions. Finally, we briefly look at how the simple inductor can transform a 12V car battery into a large enough voltage to cause a spark to jump across the gap in a spark plug and ignite the fuel in a cylinder.