I want to understand the meaning of unit impulse response when time flows. An example is given below:
In the example the left signal depicts a $\delta[n]$ function value of which is $1$ only at $n=0$. The LHS signal is response of the system to the unit impulse.
- I want to understand how to interpret this when time flows, i.e. at $n=-4,\ n=-3$, what is response of the system?
- Or at $n=0,\ n=5$, etc. what is response of the system?