For me, I consider 5 down 1 as low reps and from 8 upwards as the size building rep range. Anything above 15 I would call high reps.

I do a lot of 5 and less, occasional 8 upwards and these days not so much in the higher rep range. There was a time when I did loads of higher reps and quite a lot of the 8+ and it worked very well but for some reason I prefer lower reps as I get older. Maybe I'm weird! Maybe I just don't want to get weaker. Don't know.