How and why can a Semaphore give out more permits than it was initialized with?

Question

I am reading the book Java Concurrency in Practice. In a section about java.util.concurrent.Semaphore, the below lines are present in the book. It is a comment abou

Answer 1

I think that it means the times what we may require Semaphore as the times we released "extra" and plus the permits it created with.

Such as:

Semaphore s = new Semaphore(1); // one permit when initialize

s.acquire();
s.release();

s.release(); // "extra" release.

At this moment, this semaphore allows one permit originally and one "extra" permit