What is the fluid mosaic model? Could I get a brief description, please?

The fluid mosaic model is an interpretation of cell
membrane structure. It was proposed in the early 1970s by S.J. Singer and Garth
Nicolson. The fluid mosaic model says that cell membranes are composed of a double layer
of lipids with associated proteins. The lipid bilayer, as it is commonly referred to,
has a back to back structure - in the outer layer the hydrophilic heads of the lipid
molecules are oriented outward, and in the inner layer they are oriented
inward.

A variety of proteins are attached to and embedded
in the lipid bilayer. The attached, or peripheral, proteins include identifiers, hormone
receptors, and immune proteins. The embedded proteins create transport passageways for
the many different molecules that need to be moved into and out of the cell. The "fluid"
part of the term comes from the belief that the proteins are able to flow and move
around in the membrane.

The YouTube link below has a nice
animation that may help you to picture the fluid mosiac structure more
clearly.