What does the term "aggro deck" mean?

I think I understand what aggro means in the context of an MMO and explicitly in World of Warcraft. Arqade even has a good answer to What does "Aggro" mean?

What I am not understanding from the aforementioned links is how the term applies to an aggro deck in Hearthstone. Is an aggro deck:

• a deck which is aggressive towards attacking the opposing hero?
• a deck that aggravates the opposing hero by forcing them to attack minions instead of your hero?

I am probably reading too much into the use of the term, but each time I see aggro deck I am not sure what is being described.

Solution 1:

Aggro-deck is a term borrowed from games like Magic the Gathering. It means a deck that intends to play aggressively and kill your opponent as quickly as possible.

An aggro deck in Hearthstone is characterized by the following:

• Low mana curve (allows you to play many cards quickly)
• Aggressive creatures (high power relative to toughness) with abilities like charge, battlecry, overload and stealth
• Direct damage (burn) spells

Forcing the opponent to attack your minions with taunt rather than your hero is not a primary characteristic of aggro decks, because an aggro deck will not worry about taking damage since it is going to kill you before you kill them. An aggro deck will typically avoid playing taunt cards because the player is choosing to sacrifice defensive power for offensive strength.

Some cards that would fit the classic "aggro deck" include lava burst, reckless rocketeer, unleash the hounds, and nightblade. These cards fit because they focus on dealing as much damage to the opponent as quickly as possible, and have an effect the turn they enter the battlefield.

The opposite of an aggro deck is a control deck, which is a deck focused on removal and counters, defenses, cards that get stronger over time, and keeping a full hand of cards.

Cards that are neither aggro nor control can be referred to as "midrange" decks. Those focus on cards that are extremely efficient.