并行是指8比特数据同时通过并行线进行传送，这样数据传送速度大大提高，但并行传送的线路长度受到限制，因为长度增加，干扰就会增加，数据也就容易出错。

• 并行端口
• 串行通信

In computer science, parallel communication is a method of conveying multiple binary digits (bits) simultaneously. It contrasts with serial communication, which conveys only a single bit at a time; this distinction is one way of characterizing a communications link.