There isn’t a set standard “time signature” that producers use for all their music, however, the most commonly used is the 4/4 signature. This correlates to the time of the notes that the sequencer allows per bar.
If you use a 4/4 signature and a 1/16 note series (16th note resolution), than you will have sixteen notes for every bar for which you can input notes.
Now when you use a 4/4 signature and a 1/32 note series (32cd note resolution) you allow for 32 input notes for one bar. This is very helpful if you want to get those really fast rolls on your notes.