Where is the endoplasmic reticulum located in the eukaryotic cell?

The endoplasmic reticulum (ER) is a tubular branching cell organelle that is located in the cytoplasm of eukaryotic cells. It is an extensive network of membrane-bound flattened sacs and tubules that can span from the nuclear envelope to the cell membrane. The ER can be classified into two types, rough and smooth, based on their appearance and functions. The endoplasmic reticulum is a vital organelle in eukaryotic cells, and its functions are critical for cell survival and proper functioning.