What do these numbers mean?

[Azn_Drag0n]

When i'm in the weightroom, there are charts that tell you how many sets you should do... that's what i think anyways. It says it like 10-8-8-6 or 12-8-5. What do these mean? Are they sets or reps? i am so stupid!!

 

[holabuster]

The reps in which order for the sets.
10-8-8-6 means you do 10 reps, then 8 reps, then 8 reps, and finally 6 reps in four different sets.