set of measures lying between the lower quartile (25th percentile) and the upper quartile (75th percentile), inclusive.

the difference between the upper quartile and lower quartile

The central portion of a distribution, calculated as the difference between the third quartile and the first quartile; this range includes about one-half of the observations in the set, leaving one-quarter of the observations on each side.

This is the difference between the upper (Q3) and lower (Q1) quartiles. It is less sensitive to extreme outliers than the range, as a measure of spread of data.

The interquartile range (IQR) is a measure of spread defined as the difference between the third and first quartiles

The spread of a set of values between which 25% (25th centile) and 75% (75th centile) of these values lie

The difference between the 25th percentile and the 75th percentile.

The difference between the upper and lower quartiles of a set of numbers.

In descriptive statistics, the interquartile range (IQR) is the range between the third and first quartiles and is a measure of statistical dispersion. The interquartile range is a more stable statistic than the (total) range, and is often preferred to the latter statistic.