Wernicke-Korsakoff Syndrome (WKS) is a neurological disorder caused by a deficiency in thiamine (vitamin B1). It encompasses two conditions: Wernicke's Encephalopathy and Korsakoff's Psychosis. Wernicke's Encephalopathy is characterized by acute symptoms such as confusion, ataxia, and ophthalmoplegia, while Korsakoff's Psychosis involves chronic memory disturbances and confabulation.