An oscillation can be described in two ways. One can specify how many cycles it makes per second, also known as its frequency, or one can specify how long each of its cycles takes in seconds, also known as its period. Frequency and period are inverses of each other: frequency equals one divided by period, just as period equals one divided by frequency. For example, a frequency of two cycles per second is equivalent to a period of half a second.
In this application, a track is analogous to an oscillator, in that it cycles sequentially through its steps. A track's period, meaning how long it takes to complete one cycle, is the product of its Length in steps, and the duration of each step, also known as the track's Quant. Because step duration is measured in ticks, a track's period is also measured in ticks. For example, a track that's five steps long and has a quant of 30 has a period of 5 × 30 = 150 ticks.