Tanks, Squishys, Mages
http://pngimg.com/upload/tank_PNG1324.png This is the Tank class in a nutshell, do a ton of damage and are unkillable.
http://i.imgur.com/ywggLrK.png This is your standard adc in the early game You need to protect him so he can go from that, to this http://static.tvtropes.org/pmwiki/pub/images/Arnie_T2_minigun_6161.jpg
https://i2.wp.com/addictivelists.com/wp-content/uploads/2014/07/best-attack-helicopters.jpg This is your standard Mage/assassin, they will do way more damage then you ever expect, however can be zoned by your tanks, and if they are, you can eventually get your adc to do some damage.
Did this help explain to everyone how this game works right now?