The picosecond conversion selector selects the time measurement unit to convert to starting from picoseconds (ps). To make a conversion starting from a unit of time other than picosecond, simply click on the "Reset" button.
The picosecond is a unit of time in the metric system equal to one trillionth of a second (1 ps = 10-12 s).
One picosecond (ps) is also equal to 103 femtoseconds (fs), or 10-3 nanoseconds (ns), or 10-6 microseconds (μs) or 10-9 milliseconds (ms), which are SI units of time.
Times of this magnitude (i.e., on the picosecond time scale) are commonly used in science.