Boiling liquid in an Erlenmeyer flask.
There are several differences between the two common laboratory vessels called beakers and flasks. The main difference between beakers and flasks is their shape. A beaker is a cylinder with a pouring rim and no lid. The jars are curved without a rim and have lids. Another difference between beakers and flasks is their usage. The cups are used for careful mixing because they have a rim but they are not used for storage. Vials are used for storage and prevention of contamination by means of a cap, usually glass or rubber stopper.
A graduated cylinder is a type of cup.
Cups come in a variety of sizes, but all have straight sides and a flat bottom. The taller and wider the cylinder, the more difficult it is to accurately measure the amount of liquid in a cup. The narrower cup is called a graduated cylinder. This cup has measurement lines to determine the exact volume. Other beakers have some measurement lines, but they are not considered precise and are only used to estimate the amount of liquid in the beaker.
Vials are designed to contain and seal fluids. They usually have a wide body and a narrow neck. This allows the fluid to remain less in contact with the external environment. Vials have stoppers and caps for added containment.
Cups and jars are not made from the same materials. Jars are always made of glass and plastic, while cups are sometimes made of metals, such as tin. Cups and jars differ in variety and shape. Only a few types of cups are used, while many different types of flasks are used.
The use of beakers in the laboratory is generally for mixing and conducting chemical and physical experiments. Graduated cylinders are the only beakers used to measure volume. The most common beakers are used for mixing acids and bases with water or for other liquid reactions. A crystallizer is a short, wide cup used to dry materials that will form crystals. Beakers are not often used, but it is important to pour carefully and make observations in the laboratory.
Flasks are used to retain and store liquids for long periods of time and in a closed environment. This allows for a much wider range of uses for the jars. The vials can also be connected to other equipment with glass or plastic hoses. Virtually any reaction that produces gas will use a flask to separate the gas and measure the amount produced. Certain flasks use a vacuum pump to change the pressure in a vessel for experimental processes such as filtration.