What is the difference between Affection and Friendship, if any?

I've risen Pokemon Amie Affection to 5 hearts on my Riolo in the hopes that it will evolve as soon as it levels up, but I'm not certain that this is the same thing as friendship, and I'd like to not waste a level. My question is this: What is the difference between Pokemon Amie Affection and the Friendship stat?

You can only gain affection in Pokémon-Amie by playing with your pokémon and feeding it. When you get enough hearts, the benefits are:

• Increased Exp (1.2x, to be exact)
• Increased chances of dodging a move
• Chance of enduring a move with 1 HP
• Chance of getting rid of a status at the end of a turn
• Increased chance of getting a critical hit

However, happiness (friendship) is earned by leveling it up, giving it certain berries, going to the massage person, and walking around with it. From what I know, the effects are:

• Return does more with more friendship
• Frustration does more with less friendship
• Your pokémon evolves with enough friendship

But however, from my experience, Pokémon-Amie affects happiness as well. My little brother always played with his Kangaskhan and Return was one of its strongest moves. Whenever he got too many Poké Puffs, he would go to his Pidgeot and throw all of the Poké Puffs away because he thought it was funny. When he taught it Return, it didn’t kill a Caterpie. I’m not lying! The Pidgeot’s Frustration was like the Kangaskhan’s Return. What I concluded from this is that Pokémon-Amie slightly affects happiness as wel.

So the link that qwertyk31 supplied is also a good reference and might make this a duplicate question? But regardless here is a link to Friendship or what is also known as Happiness

And here in the other question I explain what Affection affects:What bonuses are related to friendship?

Happiness it an older game mechanic that affects evolving some Pokemon as well as moves like Return and Frustration.

As I mention in the other question, Affection affects a few other things:

• Resistant to having stats lowered
• Evasiveness increases
• Similar effect to Endure where stays at 1 hp
• Pokemon levels faster
• More critical hits( says something like ‘Pokemon Meowth is in sync with Trainer Name’)

These effects are permanent when the Pokemon's affection is full.