1. Insulators & Conductors
Conductors allow charges (electrons) to flow. Eg. metals, graphite (carbon).
Insulators hold on to their charges (electrons) tightly, so do not conduct electricity. Eg. plastics, wood, rubber, etc.

2. Cells Electrical cells store energy as chemicals.
The energy in the chemicals is transformed into electrical energy when connected to a circuit.
A battery consists of two or more cells joined together.

3. V Component Symbols + Wire Lamp Switch Motor Cell Ammeter Battery
Resistor
Fuse
Variable Resistor
Voltmeter M A V

4. Series & Parallel Circuits
In series circuits, components are connected one after the other and there is only one loop for the electrons to flow along, so the current is the same at all points.
In parallel circuits, there are two or more loops. The current is different in different parts of the circuit.