Serial port

A serial port is a <a href="/facts/Serial_communication/r5xP7P1c">serial communication</a> <a href="/facts/Interface_(computing)/zdfp8unT">interface</a> through which information transfers in or out sequentially one <a href="/facts/Bit/RwfjaYSv">bit</a> at a time. This is in contrast to a <a href="/facts/Parallel_port/qpkjH8ts">parallel port</a>, which communicates multiple bits simultaneously in <a href="/facts/Parallel_communication/9quqJd8G">parallel</a>. Throughout most of the <a href="/facts/History_of_personal_computers/d4CGfyDL">history of personal computers</a>, data has been transferred through serial ports to devices such as <a href="/facts/Modem/9H0Xwtq0">modems</a>, <a href="/facts/Computer_terminal/fSlx05qV">terminals</a>, various <a href="/facts/Peripheral/3lEBPE14">peripherals</a>, and directly between computers.
While interfaces such as <a href="/facts/Ethernet/nMfhU8tU">Ethernet</a>, <a href="/facts/FireWire/XYdQlxfy">FireWire</a>, and <a href="/facts/USB/XcIKWLyg">USB</a> also send data as a serial <a href="/facts/Stream_(computing)/2jtBAp0U">stream</a>, the term serial port usually denotes <a href="/facts/Computer_hardware/8jSjsCNv">hardware</a> compliant with <a href="/facts/RS-232/NCpvGuyq">RS-232</a> or a related standard, such as <a href="/facts/RS-485/YEABejzm">RS-485</a> or <a href="/facts/RS-422/le2rYC8T">RS-422</a>.
Modern consumer <a href="/facts/Personal_computer/koaYfNce">personal computers</a> (PCs) have largely replaced serial ports with higher-speed standards, primarily USB. However, serial ports are still frequently used in applications demanding simple, low-speed interfaces, such as industrial automation systems, scientific instruments, <a href="/facts/Point_of_sale/DwUHVn2v">point of sale</a> systems and some industrial and consumer products.
<a href="/facts/Server_(computing)/dEaYFD7r">Server</a> computers may use a serial port as a control console for diagnostics, while <a href="/facts/Networking_hardware/ck0rIkXA">networking hardware</a> (such as <a href="/facts/Router_(computing)/Nh5cIyVf">routers</a> and <a href="/facts/Network_switch/CnvmhNYT">switches</a>) commonly use serial console ports for configuration, diagnostics, and emergency maintenance access. To interface with these and other devices, <a href="/facts/USB-to-serial_converter/XLY2g50t">USB-to-serial converters</a> can quickly and easily add a serial port to a modern PC.

Serial port open-in-new

Serial port