Micro (µ) is the prefix for a millionth. In decimal notation it is zero
with 6 digits after the decimal point: 0.000.001, in exponential notation it is: 10exp-6 or 10hoch-6. The prefix micro, like all other mathematical prefixes, is defined in the Système International (SI). It is used to indicate the size of capacitances and smallest inductances, as well as for length and thickness indications: Diameter of optical fibres, distances on optical storage media, conductor tracks on chips.