Indicates that there are several types/kinds; not specifying an exact number but implying multiple varieties.
この店では数種類のチーズケーキが売られている。
This shop sells several kinds of cheesecake.
環境試料を集めて、数種類の菌を検査した。
We collected environmental samples and tested for several kinds of bacteria.
この製品は色やサイズが数種類あるので、好みに合わせて選べる。
This product comes in several colors and sizes, so you can choose according to your preference.