Classes of signals on the basis of their power and energy:

[imsanjoykb]

Energy signal– generally converging signals, aperiodic signals or signals that are bounded.
$$ E < \infty\ and\ P=0 $$

Power signal– generally periodic signals, as they encompass infinite area under their graph and extend from +\infty to -\infty.
$$ E \rightarrow \infty\ and\ P=constant $$

Neither energy nor power signal
$$ E \rightarrow \infty\ and\ P \rightarrow \infty $$