Oscillating applications revolve around the use of a capacitor and an inductor to produce a specific frequency of operation. Radio frequency circuits use an oscillator for generating a carrier frequency for data and voice signals to travel through the air. The photo of a guitar on this slide is an example of an oscillation. The strings vibrate when strummed and the frequency changes when pressure is applied on the strings or chords are changed. Each of the four main applications will be discussed in more detail as the presentation progresses.