Each one of the number level is called line or row?
For instance if I want to guide a person to look at certain sentence which is located in the level of number 4 "The grammar of English consists of all the rules etc.".
"Please, Look at the line / row 4."
If it is text, then you use line.
Finally, it introduced a standard system of reference, "through line numbering," based on the lines printed in the 1623 edition ... (Description of Norton Facsimile edition of Shakespeare).
If it's a table such as in a spreadsheet, or some kind of diagram, you use row.
The seven rows of the table, called periods, ... (wikipedia)
