Theoretical Information

The tritone is defined as a musical interval composed of three adjacent whole tones.  TT = T+T+T. The tritone is a restless interval, classed as a dissonance.

A fourth is an interval encompassing four staff positions, while a fifth encompasses five staff positions.  An  augmented  fourth  and a diminished fifth are tritones.

An  augmented fourth (Aug4) or a diminished fifth (Dim5)

Tritone resolution can be inward and outward.  

The augmented fourth resolves outward to a minor or major sixth.
The inversion of this, a diminished fifth, resolves inward to a major or minor third.
 A diminished fifth is an interval of five degrees, it is the inversion of an  augmented  fourth. Tritones are in major mode on the IV and VII  scale tones, in minor — on the VI and II  scale tones.

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