Greases are semi-solid lubricants that are used to provide long-lasting lubrication to moving parts in a variety of machinery and equipment. Unlike oils, greases have a thicker consistency, which allows them to stay in place and provide continuous lubrication, even under conditions of high vibration or shock. Greases are typically made up of a base oil, a thickener, and various additives to improve performance, such as oxidation inhibitors and rust inhibitors. They are used in a variety of applications, including automotive, industrial, and marine, and are available in different types, such as lithium-based, sodium-based, and complex soap-based, each formulated to meet specific needs and operating conditions. The choice of grease depends on factors such as temperature, load, speed, and exposure to moisture and chemicals.