Foam cups are lightweight drinking vessels made from expanded polystyrene, a type of plastic. They are commonly used for hot and cold beverages due to their insulating properties, which help keep drinks at the desired temperature. Foam cups are often found in coffee shops, fast-food restaurants, and at events because they are disposable and convenient. These cups come in various sizes, typically ranging from 8 to 32 ounces. While they are popular for their practicality, foam cups have raised environmental concerns because they are not biodegradable and can contribute to plastic waste. Many places are now exploring alternatives, such as paper or compostable cups.