Quantiles

Quantiles is an umbrella term for quartiles and other measures of distribution.
Quartiles, percentiles, and deciles are examples of quantiles used in research as statistical quantities.

Quartiles and quantiles can be visualized using boxplots.
Find the minimum - This is the lowest number in an ordered distribution. It is also known as the zeroth quantile.
Find the first quartile.
Find the second quartile
Find the third quartile.
Find the maximum- The highest number in a set of observations.

Quartiles

Four equal parts divided by three quartiles.

The median divides the data into two equal sets
The first quartile or lower quartile is the value in the middle of the first set
The second quartile or middle quartile is the median value
The third quartile or upper quartile is the middle of the second set.
Excel - QUARTILE

The inter-quartile range is the difference between the first (upper) and third (lower) quartiles.
The semi-quartile range is the difference between the first (upper) quartile and third (lower) quartile, divided by 2.

Percentiles

A hundred parts divided by 99 percentiles.

Deciles

Ten parts divided by nine percentiles.