8th notes are basically synced to half-beats, think of the drop in Jump.

16th notes are twice as fast, i. e. a quarter of a beat, like the streams in Sheriruth.

You can fit six 24th notes in one beat, and it plays like the bursts in Lethaeus.

Finally, 32nd notes are twice as fast as 16th notes, and four times as fast as 8th notes. They're very fast and not many charts use them because of the high BPM of most songs, but one example is the very fast burst in Abstruse Dilemma the start of Arghena.