A magnetic stirrer is a laboratory device used to mix liquids. It consists of a rotating magnetic field created by a magnet or an electromagnet, which drives a small magnetic stir bar placed inside the liquid. This allows for uniform mixing without the need for manual stirring, making it efficient for various scientific experiments. Magnetic stirrers are commonly used in chemistry and biology labs for tasks such as dissolving substances, maintaining consistent temperatures, and preparing solutions. They can be found in different sizes and designs, often featuring adjustable speed settings to control the mixing intensity.