LiLo and Transistors

Today I learned how to drive a relatively large output device via LiLo. LiLo can drive an LED off one of her pins because she doesnt allow some power to pass through her legs to the device. However, If i wanted to drive a slightly larger output device that require more power I would need to integrate a transistor into the circuit. How I understand to do this is, LiLo gives a very small amount of power off her leg to power a transistor. The transistor then has a gain on it that amplifies the power beyond that point. The power then is enough to supply a D/C motor, or say an incandescent Christmas tree bulb, with the necessary voltage to work. Here is LiLo and a TIP41 transistor working to power said tree blub.