Electricity is the flow of electrons through a conductor. Think of it like water flowing through pipes - the electrons are like water molecules, and the wires are like pipes.
In a circuit, electrons flow from the negative terminal of a power source (like a battery) through the circuit components and back to the positive terminal, creating a complete loop.
Voltage is the electrical pressure that pushes electrons through a circuit. It's like water pressure in pipes. A 9V battery provides more "push" than a 1.5V battery.
Current is the rate of electron flow through a circuit. It's like the flow rate of water through a pipe. More current means more electrons flowing per second.
Resistance is the opposition to current flow. It's like friction in a pipe that slows down water flow. Resistors are components specifically designed to provide resistance.
Power is the rate at which electrical energy is converted to other forms (like light or heat).
P = V × I
Power (Watts) = Voltage (Volts) × Current (Amps)
Example: A circuit with 5V and 0.1A (100mA) dissipates 0.5W (500mW) of power.
For electricity to flow, you need a complete circuit - a continuous path from the positive terminal of the power source, through components, and back to the negative terminal.
If the circuit is incomplete (open circuit), no current flows and components won't work!