Surfactant at work - arpet cleaning products work because they contain a combination of ingredients, each of which performs a specific function in cleaning carpet. The primary ingredient in carpet cleaning products is detergent. Detergents are used to break-up and remove dirt and stains and they are able to do this because they contain a chemical called a surfactant. Surfactants contain molecules that act like magnets, one end of the molecule is attracted to dirt and the other end to water. So while one end of the molecule is attaching to the dirt in the carpet, the other end is pulling the molecule toward the water in the rag used to wipe the carpet; thus the dirt is broken up, moved to the surface of the carpet and can be rinsed away.
Odor Neutralizers
Another ingredient found in carpet cleaning products that helps them to work is an odor neutralizer. Odor neutralizers function to remove the smells that are found in dirty or stained carpets. Carpet cleaning products may also contain perfumes that are designed to leave a pleasant smell in the carpet, but it is the odor neutralizer that actually cancels the unpleasant smell first. Odor neutralizers in carpet cleaners work because they contain molecules of oxygen that are activated. These activated molecules of oxygen attach to the odor-causing molecules in the carpet and change them into odor-free compounds.
Resoiling Prevention
Once carpet is clean and free of dirt and stains, it is nice to keep the carpet that way. Many carpet cleaning products have an ingredient that works to help carpet stay clean longer. A chemical called fluorine is used to prevent carpet from re-soiling. Fluorine works to repel dirt and stains because by reducing the surface tension of carpet. What this means is that dirt and stains would rather be sucked up by a vacuum or cleaned with a rag than stick to the fiber of the car.
Another ingredient found in carpet cleaning products that helps them to work is an odor neutralizer. Odor neutralizers function to remove the smells that are found in dirty or stained carpets. Carpet cleaning products may also contain perfumes that are designed to leave a pleasant smell in the carpet, but it is the odor neutralizer that actually cancels the unpleasant smell first. Odor neutralizers in carpet cleaners work because they contain molecules of oxygen that are activated. These activated molecules of oxygen attach to the odor-causing molecules in the carpet and change them into odor-free compounds. 
Once carpet is clean and free of dirt and stains, it is nice to keep the carpet that way. Many carpet cleaning products have an ingredient that works to help carpet stay clean longer. A chemical called fluorine is used to prevent carpet from re-soiling. Fluorine works to repel dirt and stains because by reducing the surface tension of carpet. What this means is that dirt and stains would rather be sucked up by a vacuum or cleaned with a rag than stick to the fiber of the car.