That girl walking down the hall texting away on her iPhone, with a case covered in owls or mustaches – she must be quite the hipster. And that guy standing outside of school on a call on his iPhone, covered in a case reading, “keep calm and throw stuff” – he must be a funny guy.

This tape deck iPhone case is just one example of the creative cases that have swarmed the halls. Photo by Anya Goodman.

A small piece of cheap material may not seem important. But anyone who owns an iPhone, or knows someone who owns an iPhone, knows a case is extremely important.

iPhone cases have become more creative and interesting as the number of teens with iPhones has exponentially increased. And what covers the phones may just be the current way for teens to express themselves to the public.

It’s like the popular picture book from our childhood: “If You Give a Mouse a Cookie.” If you give someone an iPhone, they’re going to ask for a case to go with it.

This iPhone case phenomenon has evolved immensely since its first plain black cover in 2007. There are four main ways iPhone users express their creativity through cases.

First, cases can take the form of any rectangular shaped object known to man, regardless of its size in real life. A popular example has been the rubber cassette tape, which transforms the phone into looking like an actual tape from the 90s. Other cases take the form of chocolate bars, postcards, telephone booths and more.

The second type, which is less common, but even more clever is the use of the Apple logo. Cases sometimes portray art that use the logo, like the picture of the young boy from “The Giving Tree,” who reaches out for an apple falling from the tree, in the exact same spot of the case where the logo is on the actual phone. Other designs in this whimsical category include Snow White holding the apple and Pac-Man eating it.

A third type has different textures to protect the iPhone. Bouncy rubber cases protect the phone when dropped, and waterproof cases cover the screen and its borders. Cases can also have pockets or extra compartments to hold and conceal money, cards and keys.

The fourth, and most common type, is a design or decoration. This type of case can display a famous photo or painting, a funny or emotional quote, tie-dye, denim, wood, bamboo, actual working etch a sketches – the list goes on for gigabytes.

Our generation is defined by the iPhone. And as absurd as it sounds, we can individually be defined by a 4.87-inch by 2.32-inch piece of cheap material, whether it has bunny ears coming out of the top, or looks like the ace of spades.

Everyone knows cases are crucial for protection, but they become so much more. They represent who we are. And for iPhone cases, it’s what’s on the outside that counts.