A Harmonic Progression (HP) is a sequence of numbers where the reciprocals of the terms form an Arithmetic Progression (AP). In simpler terms, if you have a series of numbers like a, b, c, then the sequence 1/a, 1/b, 1/c will be in a straight line when plotted, meaning they follow a consistent pattern. For example, the numbers 1/2, 1/3, and 1/6 form a harmonic progression because their reciprocals, 2, 3, and 6, are in arithmetic progression. Harmonic progressions are often used in various fields, including music, physics, and finance, to model relationships and patterns.