Cestodes, commonly known as tapeworms, are a type of parasitic flatworm that live in the intestines of various animals, including humans. They have long, flat bodies made up of segments called proglottids, which can grow to be several meters long. Cestodes attach themselves to the intestinal wall using specialized structures called scolex, allowing them to absorb nutrients from their host's digested food. These parasites can cause health issues, such as malnutrition and digestive problems, if left untreated. Infection usually occurs through consuming undercooked meat or contaminated food and water. Proper hygiene and cooking practices can help prevent cestode infections.