Usually...
10+ Reps = Usually strength and/or Endurance
1-3 Reps = Mainly strength training
You can do reps and sets such as 5x5 which gives you strength whilst using high volume.
I vary all the time, very rare that i go below 4 reps thoughDepends on your goal though.
If i want to get bigger, and get more ripped muscles... how many reps n sets should i do then? i want to get slightly bigger, but the goal is not like ronnie coleman style or something like that...