advantage

The advantage function $A_{\theta }(s,a)$ measures how much better taking action $a$ in state $s$ is compared to the average value of that state. Specifically, it is the difference between the Q-value (expected return starting from $s$, taking action $a$) and the state-value (expected return from state $s$):

$$A(s,a)=Q(s,a)-V(s)$$