All filters introduce some ringing, though some filters ring more than others. Filter design is a matter of compromise between different characteristics, commonly trading between performance in the frequency domain against performance in the time domain. Audacity provides a selection of filters, including the FFT “Equalizaion” filter, the biquad “High Pass” and “Low Pass” filters, and the “Classic Filters” (not enabled by default, but may be enabled in the plug-in manager).
Additional filter types may be installed as plug-ins.