What is the least count of a Digital Stopwatch?

Hint: First, we will learn what the least count for a measuring instrument means is. We will get the idea of how to find out the least count for a measuring instrument. The least count can be measured as the ratio of least reading and the total number of readings. Then we will use this idea to find out the least count of a Digital Stopwatch.

Complete solution:
By definition, we can say that the least count of any measuring instrument is the smallest and most accurate value which can be measured using that instrument. Stopwatches are the instrument that is used to measure time, mostly short events with a short duration of time. Nowadays, we have modern stopwatches that can measure parts of an event's duration along with the total duration of the event. Unlike mechanical stopwatches, digital stopwatches are more accurate, and these also contain various types of function which are useful for the experiment sometimes.
Every measurement made by the measuring instrument is a multiple of the least count of the concerned measuring instrument. Furthermore, the least count is the most accurate and smallest value measured by the instrument. The smallest yet the most accurate measure we can make is $0.01$ second in the digital stopwatch.

Therefore the least count of a digital stopwatch is $0.01$ second.

Note: The least count and precision of a measuring instrument are correlated. Remember precision of an instrument is inversely proportional to the instrument's least count. The less an instrument's least count is, the more its precision is.