The "Captain" role is a extremely important role to play when you begin a match! A important role such as the captain must defend and support heroes.
Many captain heroes rely heavily on defense and support items than such as offense. Captain heroes usually stays in the front lines, or plays as a supporting role in order to push the battle in their favor.
Captain heroes can be looked as generals, when the general is defeated the battle is lost, this also falls onto captain heroes! If captains die they will no longer be able to lead the charge leaving Junglers and Carry unable to push the battle until they have respawned. Captain's are a offense and defensive stragizer that can change the tides of battles.

The "Carry" role is the teamss greatest damage dealer while also the most fragile hero as well. The carry is one of the strongest fighters and money greedy in the holcyon fold. Carries are the quickest to gain strength and cause havoc to enemy minions, turrets, heroes, etc. Carries heavily focus on offense! Such as a solider, they pry into enemy front lines.
While with extreme damage, it comes with the cost with how fragile the hero is! Without help of other heroes such as captains and junglers, a carry by himself is not a very pretty outcome.

The "jungle" is the balanced role that plays between a Carry and a Jungle. It hides beneath home territory and gathers gold and experience points by killing monsters.
Junglers can be relied on to spring out of action and wipe out enemy forces with a surprise attsck.
Junglera have a fair shake of defense and offense.
Junglers take territory beneath the battle field and can benefit from Gold Mines and Minion Mines.
During a 15 minute period the Gold Mine will disappear and the Kraken will rise! Jungles have many advantages to mark territory with land mines and flares around that area.