An XLR cable terminates in a cylindrical metal connector plug. The connector has three holes that correspond to metal pins in an XLR port on an audio device, according to Nullmodem. The connector latches into place to prevent accidental unplugging.
XLR connections represent a technology called balanced audio. Balanced audio cables use two signal conductors, as opposed to unbalanced cables which carry all the signal through a single conductor. As the amplifier processes the dual signal, it eliminates extraneous noise for a purer sound.
Because balanced audio allows for reduced noise in their signal, professional audio engineers use XLR connections whenever their equipment includes the proper three-pin connectors. Microphones, audio or video mixing panels, loudspeakers, amplifiers and other professional audio components typically support XLR connections, according to Neutrik.