One corresponds to a whole note, two to a half note, four to a quarter note, and eight to an eighth note, and so on.

一是全音符，二是二分音符，四是四分音符，八是八分音符，以此类推。

This whole note here is worth four beats, and these little guys are eighth notes, worth half a beat each.

这个全音符为四拍，这些小家伙是八分音符，每一个为半拍。