What does the length of tye box plot mean

The box of the plot is a rectangle which encloses the middle half of the sample, with an end at each quartile.

Step-by-step explanation:

Its talking about the middle of the box

In its simplest form, the boxplot presents five sample statistics - the minimum, the lower quartile, the median, the upper quartile and the maximum - in a visual display ... The length of the box is thus the interquartile range of the sample. The other dimension of the box does not represent anything in particular.