A candy thermometer is a tool used to measure temperature, specifically designed for use in cooking and baking. It typically consists of a long stem with a bulb at one end that expands or contracts as it heats up or cools down, connected to a scale marked in degrees Fahrenheit or Celsius. The thermometer is used to monitor the temperature of syrups, sugars and other ingredients during the cooking process, ensuring that they reach the correct temperature for specific recipes before adding other ingredients such as chocolate or butterscotch. It helps prevent overcooking or undercooking, which can affect the texture and flavor of candy and confections.