The best description of one billiard ball hitting a second billiard ball is:
Most of the kinetic energy in the first ball is transferred to the second ball.
This is because, in a collision between two billiard balls, a significant portion of the kinetic energy from the first ball is transferred to the second ball, but not all of it is completely transferred due to various factors, including the conservation of momentum and energy dissipation (like sound and heat).