Steroids are considered lipids because they exhibit the primary defining characteristic of lipids, which is insolubility in water. Steroids look much different than most lipids, consisting of four carbon-based rings (three six-carbon rings and one five-carbon ring), instead of long chains.
Steroids are a class of lipids, but there are many different steroids. They differ based on the chemical units that attach to the four base rings. One well-known steroid is cholesterol, which is necessary in the body to manage inflammation. Some steroids are used for medicinal purposes, while others are used to promote muscle growth, which are called anabolic steroids.