Beakers are a type of cylindrical container used to mix chemicals, liquids and other substances together for scientific testing. They are also used routinely in laboratory experiments to calculate the volumes of various liquids. However, beakers are not the primary choice for measuring in labs, as they are only capable of providing figures within a 10 percent accuracy range.
Dr. Anne Marie Helmenstine for About.com explains that the flat bottoms on beakers make them convenient tools to place on hot plates without falling over. Beakers are usually made of borosilicate glass to prevent sudden cracking and splitting under fluctuating temperature extremes. Wikipedia notes that they can also come in other materials, such as stainless steel, aluminum, polythene, polypropylene and polytetrafluoroethylene. They are called beakers because of their small pour spouts, or beaks, located at the lip of each container.
Beakers are manufactured in a range of sizes, from tall and thin to short and stout. Each size has a different purpose. For example, tall Berzelius beakers make convenient titration tools. Beakers contain markings on their sides to indicate different volume measurements, similar to common measuring cups. Because beakers can only provide a rough estimation, the preferred instruments of choice for obtaining precise scientific measurements are graduated cylinders and volumetric flasks.