Cent
From Xenharmonic Reference
A cent (abbreviated to c or ¢) is the conventional measurement unit of the logarithmic distance between frequencies; in other words, the size of the interval between them. A cent is defined as a frequency ratio of 2^(1/1200), or a factor of about 1.0005778, such that the octave (2/1) spans exactly 1200 cents, and therefore that each step of 12edo spans exactly 100.
