Keyword Analysis & Research: why do they call it step parent

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
why do they call it step parent	1.65	0.3	2743	68	31
why	0.68	0.7	9410	90	3
do	0.18	0.8	8480	79	2
they	1.78	0.2	8950	83	4
call	1.87	0.3	9381	65	4
it	0.25	0.2	612	62	2
step	1.03	0.1	2877	72	4
parent	0.32	0.3	4215	53	6

Keyword	CPC	PCC	Volume	Score
why do they call it step parent	0.89	0.7	1885	61