Hi, I'm just starting out, and the I'm getting confused about the definition of constant HIGH on the arduino programming language reference, in the constant section, it states:http://arduino.cc/en/Reference/Constants
"When a pin is configured to OUTPUT with pinMode, and set to HIGH with digitalWrite, the pin is at 5 volts. In this state it can source current, e.g. light an LED that is connected through a series resistor to ground, or to another pin configured as an output, and set to LOW."
I don't understand the last sentence: does it say that you can configure two pins as digital output and set one to HIGH and another to LOW, and connect the two directly? Why is that useful?