Is there a difference between answering the questions:
What is the probability that a population goes extinct?
What is the probability that a population eventually goes extinct?
For example, let $p_i$ be the probability that a parent has $i$ children,
$ \ \ p_0=0.5$, $ \ \ p_1=0.25$, $ \ \ p_2=0.25$
Then, is the answer for question one, simply $0.5$, and is the answer for question two $1$ (found by solving $h(z)=z$, where $h(z)$ is a probability generating function and $z$ is the probability of eventually going extinct)? Or should the answer for both questions be $1$?