Mold and mildew have many similar characteristics, but they are different types of fungi, and are often different in color and texture. Mold and mildew are often mentioned together as they can both grow in many of the same moist and warm locations. However, mildew is often found more often than mold in showers, paper and fabrics and mold is usually found more often than mildew in foods. They can sometimes be difficult to tell apart as they both spread out from spores. Mold is often black, green, red or blue in color while mildew is usually gray or white.

The two main types of mildew are powdery and downy. Powdery mildew is commonly found on roses and other flowering plants. Powdery mildew is created by an ascomycota type of fungus. Downy mildew is from the oomycota type of fungus and is found in agricultural products such as grapes and potatoes.

Both mold and mildew thrive in damp environments, so keeping areas dry is the main preventative measure to help eliminate the fungi. Bathrooms are a prime source of mold and mildew as not only are they often damp, but they also usually do not have a lot of ventilation.

Some molds have toxins called mycotoxins that some people may be allergic to. Symptoms of a mold allergy may include headaches, asthma and coughing. Irritation of the eyes and throat may also occur as a result of breathing mold toxins. Molds are not always harmful; the antibiotic penicillin was created from the mold of the same name.

Moldy food should not be eaten. A mildew infestation on paper and some fabrics cannot be scrubbed off, but a mildew remover can usually get rid of mildew on harder surfaces such as surfaces in bathrooms. Some mold and mildew removal products should not be used by asthmatics or in an area that is not well-ventilated. Bleach solutions are often effective in killing both mold and mildew.