noun
several steps; a few levels
Used literally for physical steps or figuratively for degrees of difference. Often appears in comparisons.
階段を数段上がったところにドアがある。
There is a door a few steps up the stairs.
彼の実力は私より数段上だ。
His ability is several levels above mine.
adverb
much (better, higher, etc.); several cuts above
Adverbial use emphasizing a large gap in quality or degree. Commonly paired with 上, 優れている, or similar expressions.
この新製品は旧モデルより数段性能が良い。
This new product performs much better than the old model.
彼女の料理の腕前は私より数段上だ。
Her cooking skills are several cuts above mine.