* Cell Membrane: The cell membrane is made primarily of a phospholipid bilayer. This means it has two layers of phospholipid molecules. Each phospholipid has a head that is attracted to water (hydrophilic) and a tail that is repelled by water (hydrophobic). This arrangement forms a barrier that controls what enters and exits the cell.

* Nuclear Membrane (or Nuclear Envelope): The nuclear membrane is also made of a phospholipid bilayer, but it's more complex. It has two layers, just like the cell membrane, and is studded with nuclear pores. These pores allow for the passage of molecules like RNA and proteins between the nucleus and the cytoplasm.

So, both the cell membrane and the nuclear membrane are made of a phospholipid bilayer, but the nuclear membrane is more complex due to the presence of nuclear pores.