"Water memory" is a controversial concept suggesting that water can retain a "memory" of substances that were once dissolved in it, even after those substances are removed. This idea is often associated with homeopathy, where diluted solutions are believed to retain the properties of the original substance. However, scientific evidence supporting this claim is limited and widely debated. Critics argue that the molecular structure of water does not support the idea of memory, as water molecules are constantly moving and changing. Most mainstream scientists consider the concept to be pseudoscience, emphasizing the need for rigorous testing and reproducible results in studies related to water memory and homeopathy.