Attenuation
Maximum guaranteed reduction in power, ranging outside a specified frequency span. Spurious response attenuation is the minimum acceptable attenuation in the stop band, which allows for unwanted modes in the crystal.

Center Frequency or Nominal Frequency
Specified center frequency

Filter
A device that allows passage of a signal at a specific frequency, while blocking the passage of signals at other frequencies

Group Delay
Time taken for a narrow band signal to pass from the input to the output of a devise

Group Delay Distortion
Difference between maximum and minimum value of the group delay in a specified range of the pass band.

Hertz (Hz)
Basic unit of measurement of frequency,"Hertz" can also be used instead of the term "cycle per second". Denotes one complete occurrence of an event.

Insertion Loss
The transmitted power difference between a filter inserted or not

Insulator
Any material that does not allow electricity to pass through easily

Passband
Frequency band width in which the attenuation is the same or less than a specified value. Pass bandwidth is specified by minimum value, usually 3dB

PF
Abbreviation for "picoFarad," used to describe a fractional part, 10-12, (one trillionth) of one Farad.

Ripple
Within a pass band, it is the difference between maximum and minimum attenuation

Stop Band Width
Part of the frequency spectrum subject to specified attenuation of signal strength by a filter.

Termination Impedance
A Signal impedance and a load impedance of a filter

Transition Region
Part of the spectrum between pass band and stop band.