There are multiple types of flasks. One of the most common in a chemistry lab is an Erlenmeyer flask. This type of flask has a narrow neck and a flat bottom. It’s good for swirling, storing, and heating liquids. For some situations, either a beaker or an Erlenmeyer flask is a good choice, but if you need to seal a container, it’s much easier to put a stopper in an Erlenmeyer or cover it with parafilm than it is to cover a beaker.
Erlenmeyer flasks come in multiple sizes. As with beakers, these flasks may or may not have volume marked, and they are accurate to within about 10 percent.