A low-pass filter is the opposite of a high-pass filter. It allows low-frequency signals to pass through while attenuating or blocking high-frequency signals.
Bandstop (notch) Filter: A bandstop (notch) filter blocks out specific frequencies within its operating range, allowing all other frequencies above and below it.
Roll-off rate/slope: The roll-off rate/slope refers to how quickly a filter attenuates frequencies beyond its cutoff frequency. It is usually measured in decibels per octave or decade.