NuPIC uses a standard ML classifier to decode the neurons into a value matching the input.
At any point, the TM’s predictive cells could contain multiple predictions. The best prediction is the one with the highest probability, but others are included in case you want to parse through them.
You can set up the model to predict as many steps in the future as you want. The further out you go, the worse the predictions will be. If you choose 1,5 then you’ll get predictions for 1 and 5 steps out. You can add more, but it takes longer to process.
It is about time aggregation, and I never use it. 
I prefer to aggregate my own data.