Caitlyn's identity as a champion has traditionally been a long range ADC with excellent siege and lane bully potential. In laymen's terms, it means that her key strengths are in laning phase and pushing down towers. She has one of the highest base auto attack ranges in the entire game: only a late game Tristana, Kog'maw with W activated, or midgame Jinx in her Rocket Mode can outrange your auto attacks. As Caitlyn, you will be abusing your range advantage all game: in lane phase, you can stay out of range of most attacks and abilities, while still being about to slowly potshot and chip away at the enemy bot lane's health bars. In teamfights, you can stay further in the back line and fight from safer positions. She's also very good at kiting (this means to attack enemies while moving in a way that leaves them unable to damage you) and shines in extended late game fights. As of Patch 6.2, Caitlyn is currently one of the strong AD Carry picks, especially with several buffs given to her coming into season 6.