A conductor is represented as a simple straight line in schematics. It indicates a wire or conductive path carrying current between components. The conductor symbol is the most fundamental element in any circuit diagram.
A junction indicates an intentional electrical connection between crossing wires. The symbol is a solid dot placed where wires meet. Without the dot, crossing wires are understood to have no electrical connection.
The no-connection symbol indicates that crossing wires do not make electrical contact. It is shown as a small X or a bridge/hop over the crossing wire. This prevents misreading of schematic diagrams with complex wiring.
A terminal represents a connection point where external wires or components attach. The symbol is a small open circle at the end of a conductor. Terminals indicate points where measurements can be taken or connections made.
