Boiling flasks are used for heating and boiling of liquids. The flasks are designed to have round bodies with long, thin necks to facilitate uniform heat distribution and minimize evaporation. Boiling flasks are typically made of borosilicate glass, which is resistant to thermal shock and chemicals. Some boiling flasks have rounded or conical bottoms and need support to stand upright, while others have flat bottoms and can stand alone.

A flat-bottom flask is a laboratory glass container with a flat base and narrow neck, designed for stability and versatility in heating, storage, and reactions. Its key features are its ability to stand on its own, making it ideal for heating on hot plates or for processes on shakers, and its large, flat surface for efficient heat transfer.