When dressing up your ride to look great and to be more aerodynamic, you have several options. Whether you call the additions spoilers, splitters, air dams, wings or diffusers, there are many differences of opinions as to what is best.
So, is there a difference between options? If so, what is the difference?
Here are some definitions;
Splitters 
Front splitters are “essential aerodynamic components that serve to balance the front vs. rear distribution of downforce.” In other words, a splitter is usually located on the front end of a vehicle. They almost look like wings or flat extensions to the bottom of the bumper, kind of like a canard but much closer to the ground.
Splitters can be made from a variety of materials such as ABS plastics, sheet metal, fiber glass or, for those with means, even carbon fiber. The most advanced front splitters are those with cables that are made with springs to pull up when the wing hits something. This prevents damage to the body of the car itself as well as to the front splitter. You may now begin to understand why you’d want to protect your splitter since it is, after all the lowest point on a vehicle, but more on that in a second. First, let’s take a quick look at front lip spoilers.
Air Dams 
An air dam is often a wedge-shaped part of the lower portion of the front bumper that allows the air to pass through. Sometimes referred to as a “front lip” or “lip spoiler” it is often seamlessly attached to the front bumper, although it can also be attached as a separate piece. Unlike the front splitter, the lip spoiler isn’t a flat wing or sheet. Despite this fact, both front air dams and splitters have a similar function; to create lower and higher-pressure zones. Interestingly enough, air dams do so but are less extreme in terms of their effect whereas a front splitter’s effect increases in proportion to its sized and the speeds to which it is subjected.
Spoiler 
A spoiler makes downforce in two ways. It slows the airflow ahead of it, which increases the air pressure on the trunk lid. It also deflects air upward as it flows past the end of the car. The good news is that a spoiler makes consistent downforce. The bad news is that a spoiler also generates a lot of drag along with that downforce, so a big spoiler has a strong effect on top speed. Spoilers have proven to be effective at low speeds as well.
Wings 
Although wings and spoilers both reduce lift, they function very differently. While spoilers reshape airstreams, wings deliberately catch them, pushing the air up and the rear of the vehicle down. Rear wings increase drag significantly, so they really don’t make much sense off the track unless you like the aesthetics of them. By pushing the rear end of the vehicle down, wings ensure that the vehicles maintain stability even while making incredibly fast turns.
Diffusers 
Another way to generate a low-pressure zone to increase downforce is to use a rear diffuser. True to their name, diffusers help to direct the air as it makes its journey underneath your car so that it doesn’t create too much drag. As you can imagine, much like splitters, these modifications don’t do much for cars that sit high above the road. On a sporty car though they can also contribute to the overall ‘look’ of performance and speed.
There are many varieties of each option. Once you decide what effect you desire for your ride, check out all the different products that are available.