Quartiles

This is quarters
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

Inter-Quartile

The inter-quartile range is the difference between the upper and lower quartiles.

Semi-Quartile

The semi-quartile range is the difference between the upper quartile and the lower quartile, divided by 2.

Deciles

This is tens