Numbering sequence in a hierarchy: level

In a hierarchy, level is the position of a segment in the hierarchy in relation to the root segment. The root segment is always on level one.

The following figure illustrates levels of the database record shown in Relationship between segments.
Figure 1. Levels in the database
Level 1 has the Math segment. Level 2: James, Baker, Coe, and Room2. Level 3: ReportA, ReportB, Pass, and Inc.