One of the important properties of liquids is their resistance to flow, which is called viscosity. The higher the resistance of the liquid, or in other words, the later it flows, it is said to have a lot, and conversely, if it shows less resistance to flow, the lower the viscosity of the liquid.
Flow resistance is more related to gravity between molecules, and measuring the viscosity of a liquid gives a simple estimate of the strength of gravity. In general, as the temperature rises, the ability of the adhesive forces to withstand molecular motion decreases, resulting in a decrease in viscosity. But increasing the pressure usually increases the viscosity.
Measuring the viscosity of liquids in different ways is called viscometry, and the tool used to do this is called a viscometer. There are different types of viscometry that can be preferred over each other depending on the type of fluid and the test conditions.