What is the difference between ionization energy and electron affinity?

Ionization energy is the amount of energy required to remove the electron that is most loosely bound of an isolated gaseous atom to form a cation.

Electron affinity is the amount of energy released when an electron is added to a neutral atom or a molecule in a gaseous state to form negation ion.

The difference of ionization energy and electron affinity is ionization energy is the required energy to remove an electron from a neutral atom. Whereas, electron affinity is the energy change when a neutral atom attracts an electron to become a negative ion.