The columns (or rows) that have the same initial consonant are labeled as the first item in that column (consonant + a) followed by 行. Examples of such are あ行, か行, さ行, た行, etc.

The rows (or columns) that have the same vowel sound are labeled with that vowel in hiragana (あ, い, う, え, or お) followed by 段. Thus, the five rows are labeled as あ段, い段, う段, え段, and お段.

One exception for both of these is ん; it's just its own thing.

The chart on [this Wiki page](https://ja.wikipedia.org/wiki/%E5%B9%B3%E4%BB%AE%E5%90%8D) illustrates better what I'm talking about.