Reusable cups are containers designed for multiple uses, often made from materials like stainless steel, glass, or BPA-free plastic. They are popular for beverages such as coffee, tea, and smoothies, helping to reduce waste from single-use cups. Many reusable cups are insulated, keeping drinks hot or cold for extended periods. Using reusable cups can contribute to environmental sustainability by minimizing the amount of plastic waste in landfills and oceans. Some cafes and restaurants even offer discounts to customers who bring their own cups, encouraging more people to adopt this eco-friendly practice.