What are the essential features of lipids?

Lipids are naturally occurring organic compounds that include fats, oils, and certain steroids. They are present in almost all living organisms in this ecosystem. They play immense roles in the cells of living organisms. Almost all lipids are insoluble in water and are known as hydrophobic since they are water-repellent.
They have many important roles. The most important function lipids perform is serving as the building blocks of cell membranes. Other functions include energy storage, insulation, and cellular communication and protection. Lipids also allow for the absorption of fat-soluble vitamins like A, D, E, and K, which are very much essential for the body.
Cell membranes are made up of a double layer of lipids known as phospholipids. This phospholipid layer creates a barrier for substances moving in and out of a cell, thus providing a protection.
Fat (lipid) molecules can store very high amounts of energy, which is needed for the body to perform day-to-day activities. Fats are important for insulating the body from outer temperatures, especially in the case of some marine animals. In order to prevent themselves from freezing water, they have a thick layer of fat to keep them warm. Fats also provide a protective layer around important organs like the liver and kidneys.
Steroids are a group of lipids that are involved in cell-to-cell communication. Most steroids are hormones and are important for many processes in the body, including growth, sexual development, regulating metabolism, and immune defense.
https://basicbiology.net/micro/biochemistry/lipids