What is what does mm mean in text?

In text, mm is often used as an abbreviation for "millimeter" which is a unit of measurement in the metric system equal to one thousandth of a meter. It can also be used as an informal abbreviation for "minute" or "moments" to indicate a short duration of time. In addition, mm may be used in online forums or messaging platforms as an expression of agreement or acknowledgement, similar to "yes" or "okay."