Frequency
In mathematics, frequency is the reciprocal of time; hertz is one type of unit of frequency. It is typically associated with waveforms that resonate, for example, in communications, weapons, shields, and cloaks.

Types of frequencies 
 Cloaking frequency
 Communications frequency
 Resonance frequency
 Shield frequency
 Spectral frequency
 Transponder frequency
 Warp frequency

See also 
 Frequency spread
 Frequency log
 Frequency modulation
 Frequency scan detector

External link 
 

de:Liste von physikalischen Größen und Maßeinheiten#Frequenz
Mathematics