yes bitcoin is a digital money
you can use this anywhere. online pament aur invest and saving
Is it better to save money in bank or invest it online, in real
estate or maybe gold?

If you trust bitcoin, i think better you save your money at bitcoin
i save some of my fund every week at my vault address
also i save some of that at $
Saving in bitcoins at a moment is the right thing to do as the value of bitcoins is low at present so buying bitcoins at a moment is a good idea and saving it and keeping it safe in digital wallet for the future would serve the purpose as we believe that the value of bitcoins would go higher in the coming future so it is better to save money in bitcoins and be patient.