When selecting a filter implementation one factor that is common across all frequencies is optimizing the size of the filter given the application and the required performance.
An ideal filter
The Ideal Filter would have unit gain (0dB) in its pass band and a gain of zero (-infinity dB) in its stop band. Between pass band and stop band there would be no indecision and would transition from 0dB to -infinity dB asymptotically. It would pass only the required frequencies without adding or subtracting anything from the signal and like a very discrete and fastidious butler we would not see it - just its perfect management of the frequencies in its care.
This document is designed to act as a quick reference on some terms that are used to discuss filter technology.
There are four key Filter behaviors that sort them into types: Low Pass, High Pass, Band Pass and Band Stop.