Hi Abhishek,

Standard deviation is a measure used to identify how much the data varies in a group of data.

Suppose,

The runs scored by Virat Kohli is 100, 102, 86, 87, 91

Since the values are nearby, it means runs scored by Virat Kohli have less standard deviation.

Now, suppose

Runs scored by Shikhar Dhawan are 1, 3, 0, 23, 101

Since the values differ a lot, it means runs scored by Shikhar Dhawan have high standard deviation.

Check formula of Standard Deviation and variance here https://www.teachoo.com/5683/1804/Chapter-15-Class-11th-Statistics-Formula-Sheet/category/Chapter-15-Class-11th-Statistics/