The two-pin type function same as quartz,but have not too exact frequency: e.g. 4.00MHz (quartz available 4.0000Mhz) low cost,and excellent for any PIC application.(not for freq.counter)Called as resonator.
Avilable with 3pins with built-in capacitors.
The ceramic filters available with different caracteristic:bandpass,notch e.t.c. E.g. SFE10.7 for for FM-IF stage.The function same as coil, but no need adjustment. CDA 5.5 for TV-sound discriminator stage.
SAW-filters for TV-tuner output to separation of video IF and sound IF....
and many more...