In notes of prof. W.Stein - http://wstein.org/edu/2010/581b/stein-algebraic_number_theory.pdf - the first paragraph of page 112 has the following told:
"When $K$ is a perfect field, the prime ideals correspond to the Galois orbits of affine points of $E(\bar{K})$."
I would be thankful if someone could elaborate what is meant here by the Galois orbits of points of $E$ and what is the implied correspondence.
Thank you!