parallel
RS-232
usb is more efficient
Serial communication is preferred over parallel communication for long-distance WAN links primarily due to reduced crosstalk and electromagnetic interference. In parallel communication, multiple wires transmit data simultaneously, increasing the risk of signal degradation over long distances. Serial communication, using a single wire or pair, minimizes these issues and simplifies the design and implementation, allowing for higher data rates and longer transmission distances without significant loss of integrity. Additionally, serial connections require fewer physical resources, making them more cost-effective for WAN applications.
Parallel data transmission is faster compared to serial data transmission. The speed of a parallel link is equal to the number of bits sent multiplied by the bit rate of each individual path.
A serial wire can be used for several uses. Mainly, it's used for basic communication between different devices. The main advantage is the fact that serial communication can use only three wires. Parallel requires several more, typically eight, or sixteen, plus signalling, and traditionally is faster. But for simple communication between devices, which could be computers or other devices, serial communication can simplify things. Serial communication can also be used for great distances. The telegraph was serial communication. Hence "AT&T"!
Neither. A computer case is just a box to hold the parts of a computer. It provides no form of communication itself.
Depends, is the device serial or parallel?
Telephone communication was introduced by Gram bell.
On the telephone side, they are usually connected via a telephone cable to a wall telephone walljack. On the computer side they usually connected via a serial cable to the computer's serial port. Serial ports can have either 9 pin or 25 pin connectors, and so are often confused with parallel ports, which also can have 25 pin connectors.
parallel
Parallel port communication cable length 8 channel is easy to form the mutual interference between the transmission speed and distance are limited, and when the transmission error, at the same time to the eight bits of data, and a serial port without interference, transmission error after it is ok to resend a, so faster than parallel port. Therefore generally parallel communication without transmission distance, serial communication, serial port communication is generally not more than 30 meters, but also the specific see the baud rate of the transmission signal, so the parallel communication estimated only a few meters, there is no exact definition of data.
multiplexer can be used as parallel to serial converter.