A shower liner is a waterproof barrier that hangs inside a shower or bathtub to prevent water from leaking onto the bathroom floor. Typically made from materials like vinyl or polyester, it helps keep the area dry and protects against mold and mildew growth. Shower liners are often used in conjunction with a decorative shower curtain. These liners come in various sizes and styles, allowing them to fit different shower setups. They are easy to clean and can be replaced when worn out. Many people choose to use a shower curtain along with a liner for added aesthetic appeal.