Ceramic fiber insulation and plastic foam insulation differ in several aspects. Ceramic fiber insulation, often made from materials like alumina-silica, offers high-temperature resistance and is non-combustible, making it suitable for high-heat applications. It's also known for its thermal stability and resistance to thermal shock. On the other hand, plastic foam insulation, such as polystyrene or polyurethane, is lightweight, easy to install, and provides good thermal insulation at lower temperatures. It's less resistant to high temperatures and can be combustible, but it's cost-effective and has good acoustic properties. The choice between them depends on the specific application's temperature range, fire resistance requirements, and budget considerations.