electronegativity vs electron affinity

[Divya Pimparkar 1E]

What's the exact difference between electronegativity and electron affinity?

[Aurbal Popal]

Electron affinity is the energy released when a gaseous atom gains an electron. It is has units (kJ/mole).
Electronegativity is a relative measure (does not have units as it cannot be directly measured) of the tendency of an atom to attract a pair of electrons in a covalent bond. From my understanding, electron affinity and ionization energy impact how electronegative an atom is.

[Mhun-Jeong Isaac Lee 1B]

Another way to look at it is how my TA defined them:
electron affinity = how much an atom "wants" an electron
electronegativity = polarizability, attracts electron in a bond

[ran2000]

Electron affinity is calculated for gaseous atoms (the energy change when an electron is added to the gaseous atom) and its unit is kJ/mol. This is experimentally derived.
Electronegativity is the tendency of an atom to attract electrons towards in a bonded state and is for bonded atoms only. It is not experimentally derived, rather calculated.

[Jchellis 1I]

I don't know how correct this advice I was given is, but I was told by another Chem14A TA that we don't really need to know the concepts behind why they are different in order to do the problems we are given in the Chem14 series.