A nanosecond (ns) is an SI unit of time equal to one billionth of a second ( 1/1,000,000,000s). A nano-unit is 10 raised to the power -9. One nanosecond is to one second as one second is to 31.71 years. The prefix nano and time's unit second led to the formation of the word nanosecond whose symbol is given as ns. There are still two more units smaller than nanosecond, these are picosecond (1/1,000,000,000,000s) and femtosecond(1/1,000,000,000,000,000s). One thousand nanosecond will make up 1 Microsecond whereas a million nansecond is equivalent to 1 millisecond. The unit nanosecond is generally used in computers to calculate the processing time of RAM and in electrical components.