Which action is a subscription to a response?

Question

Toaster

Got the first change notification today, but I wasn't subscribed to the question. The only answer was marked with a like and a solution. What does it mean to subscribe to an answer?
And one more additional question. It turns out that if I change my answer somewhere, then all the "subscribers" of the answer will receive a notification, even if they are not subscribed to the question?

Answer 1

a like is enough to be notified when the answer is changed.