This document introduces basic components of DC circuits. It defines a complete circuit as one where electron flow can travel from negative to positive terminals, and an incomplete circuit as one where flow is disrupted. Circuits must have four basic components: conductors to carry current, a load that uses power, a power supply to provide energy, and optional controllers to manage the circuit. Schematic symbols represent components in schematic diagrams, which are blueprints showing a circuit's construction. Common symbols are introduced for wires, loads like LEDs, power sources like batteries and cells, and switches as controllers. Assignments include an electronics reference chart to document websites on topics.