A pipette is a laboratory tool used to transport a measured volume of liquid, often as a media dispenser. It is commonly used in chemistry, biology, and medicine. Pipettes come in a variety of sizes, shapes, and designs, and they are made of either plastic or glass. The word "pipette" comes from the French word "pipette," which means "little pipe". There are several types of pipettes, including:

• Volumetric pipette: Used to measure and dispense a single, predetermined volume of liquid with exceptional precision.
• Graduated pipette: Marked with a series of graduations to indicate different calibrated volumes, similar to a graduated cylinder or burette.
• Measuring pipette: Has graduated volumes and can dispense different volumes, calibrated with small divisions and often adjustable.
• Micropipette: Accurate and precise, used to transfer measured volumes of microliters of volume, and often used in microinjection and measuring experiments.
• Pasteur pipette: Similar to an eye dropper, used to transfer a small amount of liquid, and not calibrated to a specific volume.

Pipettes work by creating a partial vacuum above the liquid-holding chamber and selectively releasing this vacuum to draw up and dispense liquid. They are used to transfer or measure precise volumes of liquid, and they are essential tools in many laboratory experiments.