Which component do only triglycerides have in common?

Triglycerides are composed of a glycerol backbone and three fatty acid chains. This unique structure is what distinguishes triglycerides from other types of lipids. While both phospholipids and triglycerides share a glycerol backbone, phospholipids additionally contain a phosphate group and often have different fatty acid compositions, leading to distinct properties and functions.

Steroids, on the other hand, have a completely different structure characterized by four fused carbon rings and do not contain a glycerol backbone. Fatty acid chains are present in other types of lipids, such as phospholipids, which consist of two fatty acid chains attached to a glycerol backbone. Therefore, the glycerol backbone is the only component found exclusively in triglycerides when considering the unique structural aspects of these lipid types.