When to Use Variance vs Standard Deviation?

Variance is a method to find or obtain the measure between the variables that how are they different from one another, whereas standard deviation shows us how the data set or the variables differ from the mean or the average value from the data set.

Why would you use variance over standard deviation?

This makes standard deviation easier to interpret. Variance weights outliers more heavily than data very near the mean due to the square. A higher variance helps you spot that more easily. Also, mathematically/theoretically speaking, dealing with variance is easier.

Which is better variance or standard deviation?

The SD is usually more useful to describe the variability of the data while the variance is usually much more useful mathematically. For example, the sum of uncorrelated distributions (random variables) also has a variance that is the sum of the variances of those distributions.