The idiom, "reinvent the wheel," is an English saying of unknown origin that is largely used to describe an exercise in futility. Many people will say, “Don’t reinvent the wheel” when they are starting upon a task, meaning that some foundational aspects of the task don’t need to be changed or replicated, as this would be a waste of time. The wheel in this idiom refers to the actual invention of the wheel, and the fact that this invention changed human history, and could be considered a near perfect advancement. The term can stands as symbol for advances in various forms of technology that are thought relatively perfect and don’t require reinvention in order to build something else.
It’s perhaps easier to understand why people wouldn’t want to reinvent the wheel with a concrete example. A computer programmer who is creating a video game may rely on the specific programs already in place to do so. He doesn’t build a game system from the ground up, but instead works to create a game that will fit within an existing system. Provided the goal is just to produce a good video game, the programmer can merely pay attention to existing programming laws and systems to create one.
This example actually includes some of the reasons people have problems with the idiom, reinvent the wheel. Suppose the programmer really wants to create a new and exciting game for a new system. He might very well decide to start by building a new system from the ground up that could allow for greater gaming functionality. Creating the Nintendo Wii®, for example, which allows people to incorporate movement into gaming is a reinvention of the wheel, and arguably a fun and good one. The question becomes what is to be profited when people reinvent existing systems? Sometimes that answer is that there’s much to gain.
Of course, even within this example, not all things are reinvented. The new game system may not reinvent the wheel with basic electronic elements. It may still plug into a wall for instance. Not all aspects have to be newly created in order to change or improve something. Wheels today are still round, but they’re seldom made out of stone, a fact for which anyone wishing to conserve gas can be highly grateful.
A related phrase is “don’t reinvent a square wheel,” which generally means don’t go back to the basics and invent something that isn’t as good as the original. This may reflect a fear that keeps people from branching out and trying new things. Yet sometimes it's necessary to look at the most basic elements of construction in order to see if an accepted design is really as applicable as it could be. Obviously invention has certain come up with some “square wheels,” but it has also developed things the inventors of wheels could never have dreamed possible.
A few people may argue that reinventing the wheel has some purpose. This is why there are many classes in engineering and physics and at high school and grammar school levels where students rebuild very simple machines. Actually working on these machines may give people an appreciation for the thought and skill it took to create something. It offers hands on experience instead of asking students to take for granted the massive achievements of even small and basic creations.