The Smooth Endoplasmic Reticulum (SER) is a type of organelle found in eukaryotic cells. Unlike its rough counterpart, the SER lacks ribosomes on its surface, giving it a smooth appearance. It plays a crucial role in the synthesis of lipids, including fats and hormones, and is involved in detoxifying harmful substances within the cell. Additionally, the SER is important for storing calcium ions, which are vital for various cellular processes. It is often found in cells that are actively involved in lipid metabolism, such as those in the liver and adrenal glands, contributing to overall cellular function and health.