Created by Danny Kallis and Jim Geoghan, Zack and Cody Martin are identical twin brothers that reside at the fictional Tipton Hotel's flagship location in Boston in the original series.

Throughout the course of both series, the Martin brothers experience the hallmarks of adolescence, such as friendships, academics, bullying, peer pressure, sibling rivalry, parental communication, relationships, and maturity.

The Martin brothers have also appeared in multiple crossover episodes of other Disney Channel series, including That's So Raven, Wizards of Waverly Place, Hannah Montana, I'm in the Band, So Random!, and the special Studio DC: Almost Live.

[3] In the episode of The Suite Life of Zack & Cody titled "Poor Little Rich Girl", however, a baby video of the two is date-stamped September 23, 1992.

He also tends to be more caring, sensitive, polite, and more well-behaved than his brother, but even he is not perfect; he occasionally shows acts of meanness and greed.

Despite his exceptional intelligence and relative maturity when compared to Zack, Cody exhibits some comically regressive behaviors, such as calling his mother "Mommy", screaming when frightened, and carrying a "blankey" into his teens.

After traveling around the nation, the twins and their mother Carey arrive in Boston, residing in the Tipton Hotel.

Cody and Zack become friends with Maddie Fitzpatrick, they each keep a picture of her in their rooms when they move to the SS Tipton.

Cody does well in school and is interested in several intellectual activities, which results in him attending math camp and winning a spelling bee.

As the show progresses, his character develops into a type who generally only gets in trouble by mistake or (more often) due to Zack's influence.

[13] During the third season, Cody works part-time as a bag boy at the Paul Revere minimart over the summer holidays.

[14] Zack initially shares a room with Bailey Pickett, a smart and intelligent student, who's a girl disguised as a boy.

In the third season they are still good friends but are shown to still have feelings for each other until they finally get back together and agree to a long-distance relationship in "Graduation on Deck" while they are both in college.

In "Graduation on Deck", the series finale, Maya joined the Peace Corps in Africa, and as a result, breaks up with Zack, because she could not handle a long-distance relationship.