A water bath canner is a large pot designed for preserving food through the canning process. It typically has a lid and a rack to hold jars above the boiling water. This method is ideal for high-acid foods, such as fruits, pickles, and jams, as the boiling water helps to kill bacteria and seal the jars. To use a water bath canner, jars filled with food are placed in the pot, which is then filled with water and heated to a rolling boil. The jars must be submerged in water for a specific time to ensure proper sealing and safety. This method is popular among home canners for its simplicity and effectiveness.