Orange is depicted as an exasperating anthropomorphic orange. He is the central character in the series, though not always the main character in some episodes.
Orange is disliked by many characters, because he heckles them in many ways, such as spitting seeds, mistaking them for other things, and making childish noises. In the episode More Annoying Orange, another Orange comes and actually annoys Orange, which is in contrast to what it is originally. Not much is known about Orange's past, but it is confirmed that he actually was born the day he debuted.
It is unknown if Orange gets such joy of annoying other people, but on possibility is that any other orange is like that. Another possibility is that he just likes puns and jokes, and doesn't pay attention to how people is being annoyed, according to his friend Passion Fruit.
In October 9, 2009, Orange was born and put on the counter in Dane Boedigheimer's kitchen where he met Apple, who he annoyed some time before the first episode was recorded. He has met oodles of fruits and vegetables, and usually infuriates him, and some survive (much to their horror). He is a friend of Pear.
Later in the series he meets Passion Fruit, who he has some feelings for, and Passion thinks of him as a friend most of the time.
Orange is a major part in the kitchen as seen in Wishful Thinking, because if Orange didn't exist, Pear wouldn't know how know how to talk to other fruits and vegetables, Midget Apple of injured Grapefruit, and Marshmallow would have been killed by hot chocolate. He currently lives in the kitchen and shares counter space with Pear and Passion Fruit (and in some episodes Grapefruit)
Marshmallow and Orange are good friends, and they have shared may adventures together (sometimes even private), and Orange cares very much for Marshmallow (as seen in Wishful Thinking, when Orange was horrified by the death of Marshmallow).
On Orange and Grandpa Lemon's first meeting, Orange was constantly annoyed by Grandpa Lemon's tendency to fall asleep and his bad hearing, but after Grandpa Lemon's resurrection, they have remained friends.
Grapefruit and Orange is generally enemies, and Orange calls him "Chubby McChubby Orange", and Grapefruit also uses puns, but aside from Orange, Grapefruit means to annoy, terrorize and hurt people with his puns and other mean things.
"Wanna hear the most annoying sound in the world?"
"Hey, guys, what's so funny?"
"Hey, Yo. It's A to the O back again with another gaming video!
"Downtown James Brown!"
"Dang, Daniel at it again with the white top hat!"
"I hate you, Blimp!"
"Doing a barrel roll!"
"He did a barrel roll."
"My ketchup packets!"
"You rub your mustache on me!"
"Alright, Guys. Thank you for watching. Make sure you like, favorite, subscribe button to everything you can to make it the most popular video in the internet because it was so good. Alright, Guys until time... Later, Hot-Potaters!"
Why? Why you gotta be rubbin' your mustache on me?