A high-pass filter (HPF), also called a low-cut filter, attenuates frequencies below a set cutoff point. Frequencies above the cutoff pass through unaffected. The cutoff frequency is usually expressed in Hz — an 80 Hz high-pass filter removes sounds below 80 Hz.
In recording, HPFs are used to eliminate unwanted low-frequency content that adds nothing to the sound: HVAC rumble (15–50 Hz), handling noise from mic stands (below 100 Hz), wind noise in outdoor recording, proximity effect bass boost, and the low-frequency hum from electrical interference.
Many microphones and audio interfaces include a switchable high-pass filter, typically set at 80 or 100 Hz. In a DAW, every equalizer plugin includes a high-pass filter that can be set to any frequency with a variable slope.
For voice recording (podcast, voice-over, streaming), rolling off everything below 80–100 Hz is generally safe and beneficial — very few voice fundamentals exist below 80 Hz, and the energy in that range is almost entirely noise and rumble.