Heroes

Heroes are the essential element of Dota 2 as the course of the game is dependent on their intervention. Players are split into teams of 5 vs. 5 and select a Hero from an existing pool. Heroes all have different play styles that stem from unique Skills and combinations of Attributes. Over the course of the game, Heroes will accumulate Experience. Once a Hero has enough experience, they will level up, making them more powerful than before and allowing them to train a new Skill. Most Heroes have a distinct Role that defines how they can effect the battlefield, though many Heroes can perform one or more of these Roles.

Roles
Heroes are given different Roles based on their strengths and weaknesses on the battlefield. Though a Hero may be assigned a Role in game, he's more than capable of performing as any other Role. For example, Supports can also be Gankers, or Pushers can be Carries. However, many Roles share similar traits.
 * Carry Heroes are Heroes that are dependent on their Skills and Items in order to be successful. Usually, they start out weak, but become a lot stronger later in the game. A Carry depends on a lot of Experience and Gold to reach their maximum potential. Having too many Carries will cause competition within your team for resources, which will end up slowing down everyone. It is recommended that a team have only one or two Carry Heroes.
 * Examples of Carries include Anti-Mage, Sniper, Spectre, and Drow Ranger.
 * Support Heroes typically assist other Heroes by keeping their allies alive and giving them opportunities to earn more Gold and Experience. Supports will usually come with Skills that deal Stun or can otherwise Disable enemies in order to prevent them from attacking friendly Heroes, or make them an easy target. Support Heroes are not as dependent on Items and Experience in order to be successful.
 * Examples of Supports include Lich, Necrolyte, and Vengeful Spirit.
 * Ganker Heroes specialize in taking out enemy Heroes quickly. They stop enemy Carries from farming properly and harass other Heroes in order to prevent the enemy team from getting levels, skills, and items they need. While Support Heroes might focus on defending their teammates or rendering enemies useless, Gankers believe more in offensive tactics, and concentrate on early game kills to hinder enemy income.
 * Examples of Gankers include Ancient Apparition, Zeus, and Nature's Prophet.
 * Initiator Heroes are built for a team fight. They typically engage enemies first, either as a distraction or a tank, while the rest of the team follows suit. Usually they have one or two skills that put the enemy team at a large disadvantage, especially useful before a large fight. They specialize in impairing enemies and then keeping them impaired for the rest of the fight.
 * Examples of Initiators include Tidehunter, Earthshaker, Axe, and Puck.
 * Pusher Heroes concentrate on building up creep waves and taking down towers. Their goal is to put pressure on the enemy team, forcing them away from grinding income, and finishing the game before the enemy Carry can become unstoppable. Pushers typically have skills that fortify creep waves, summon minions, or decimate enemies.
 * Examples of Pushers include Leshrac, Chen, and Enigma.