Why A schematic is the standard drawing that represents a circuit using agreed-upon symbols for resistors, capacitors, transistors and so on, plus lines showing the electrical connections between them. It shows how the circuit works electrically, not how the parts are physically arranged on a board or in a chassis. Because the symbols are standardized, any ham anywhere can read the same diagram.
Watch out A flow chart shows steps in a process or program, not electrical connections, and a connection or wiring chart deals with physical cabling rather than standard component symbols.
Schematic = scheme of the circuit in symbols; flow charts are for processes, not parts.