a boom mic is a type of microphone which is mounted (usually with shock absorbing springs or chords to avoid noises) at the end of a "Boom pole" or "fishing pole" which itself is a long extendable/telescopic pole that allows the Boom Operator to reach OVER a presenter or actor and lower the microphone as close in to a presenter or actors direction of speech but WITHOUT the boom pole or rod (or MIC) appearing in the frame.

The microphone used at the end of the boom pole is USUALLY a "shot-gun" or "directional" microphone which is therefore often called a BOOM Mic