AC - Abbreviation for alternating current, which is voltage that flips back and forth between positive and negative.
Ampere - Unit of current (symbol: A).
Breadboard - A board used to make temporary circuits. The breadboard has metal-lined sockets for connecting electronic components in a test circuit.
Capacitor - An electronic component consisting of two conducting surfaces, separated by an insulator. It is used to store and release energy and to control high-frequency signals.
Circuit - A collection of electronic parts connected together, usually designed to perform some kind of function.
Circuit diagram - A diagram that depicts a circuit, using symbols for electronic components. Used to design and communicate circuits with other people, like a blueprint or a plan.
Closed circuit - A circuit in which current can flow through electronic components, from a point of high voltage to a point of low voltage.
Conductance - The opposite of resistance. Materials with high conductance (e.g. metals) have low resistance. The unit of conductance is siemens (S).
Current - The flow of electric charge. The unit for current is amperes (A).
DC - Abbreviation for direct current voltage, which is voltage that does not alternate.
Diode - An electronic component that allows current to flow freely in only one direction.
I - Symbol for current. The unit for current is the ampere (A).
Integrated circuit (IC) - An electronic component that contains several simpler electronic components. An IC is a miniaturized electronic circuit.
Jumper - A short length of wire used to temporarily complete a circuit or to bypass a break in a circuit.
Kilo - A prefix meaning "thousand." A 10-kΩ resistor is 10,000 ohms.
Lead - Length of wire used to make connections between components in a circuit.
Light-emitting diode (LED) - A solid-state device that has two key features: it allows current to flow in only one direction (that is the "diode" part), and it emits light when current flows through it in the "allowed" direction. LEDs are described by several specifications, some of the more important of which are:
Maximum current;
Brightness;
Color of light;
Angle of light beam (for example, an LED with an angle of 15 degrees produces a more focused beam than one with a beam of 45 degrees); and
Size, usually 5 mm.
