Cleanliness is both the state of being clean and free from germs, dirt, trash, or waste, and the habit of achieving and maintaining that state. Cleanliness is often achieved through cleaning. In most cultures, cleanliness is considered a good quality, as indicated by the aphorism: "Cleanliness is next to Godliness", and may be regarded as contributing to other ideals such as health and beauty.
The concept of cleanliness emphasizes an ongoing procedure or set of habits for the purpose of maintenance and prevention. In this it differs from purity, which is a physical, moral, or ritual state of freedom from pollutants. Whereas purity is usually a quality of an individual or substance, cleanliness has a social dimension. "Cleanliness", observed Jacob Burckhardt, "is indispensable to our modern notion of social perfection". A household or workplace may be said to exhibit cleanliness, but ordinarily not purity. Cleanliness is also a characteristic of people who maintain cleanness or prevent dirtying.