Final answer:
Serial cables used on computers typically have either 9 or 25 wires, depending on the type of serial connection. The wires are used for transmitting data, control signals, and power between devices.
Step-by-step explanation:
A serial cable used on computers typically has either 9 or 25 wires, depending on the type of serial connection. A common type of serial cable used in computers is the RS-232 cable, which has 9 wires.
These wires are used to transmit data, control signals, and power between devices. Each wire has a specific function, such as transmitting data bits, controlling flow of data, and providing voltage levels.
For example, the RS-232 cable has wires for transmitting data (TX), receiving data (RX), ground (GND), and other control signals like Request to Send (RTS) and Clear to Send (CTS).