What is the difference between mould and mildew?

Mould and mildew are both types of fungi which are similar in many ways but have major differences in appearance, texture, and how they affect your health. Mould is usually fuzzy and can vary in color. Mildew grows in a flat pattern, may appear powdery, and over time changes color. While both are known to cause respiratory and allergy-like symptoms, mould can cause structural damage and more serious health problems, including neurological issues.