using ohm's law we can figure out how much amperage/ resistance/ or voltage is being used in a circuit. it is represented by a triangle that shows V/I*R. Open circuit? you could put a switch there.
circuit is a continuous path for electricity and current
open circuits are breaks in those paths
short circuits are when power connects directly to ground. or highest potential to lowest potential.
Power is "usually" coded red on the bread board
T package LEDS usually come In Red Yellow or Green and operate on 3v and 20mA. this is why we need a resistor. LEDs are polar meaning they control the flow of current. This is important because they can shut down the whole circuit. The short leg of the LED or the Flat spot or the bit thats bigger inside the lens is the negative leg.
ICT internet communication technology. books on this medium is the massage Marshall McLuhan. He theorizes that the medium changes what you say. Every medium has it's limitations.