A high-pass filter is the opposite of a low-pass filter. It allows high-frequency signals to pass through while attenuating or blocking low-frequency signals.
Bandpass filter: A bandpass filter is a combination of a low-pass and high-pass filters. It allows a specific range of frequencies (a band) to pass through while attenuating frequencies outside that range.
Cutoff frequency: The cutoff frequency of a low-pass or high-pass filter is the frequency at which the output signal power drops by half (-3dB) compared to the input signal power.