Fluid mosaic model was designed by Singer and Nicholson in 1972 to describe the features of biological membranes. They wanted to picture out the the structure of the cell membrane in its most simple way.
1. The called it fluid because of the hydrophobic tails of the lipid membrane tend to sway sideways or lateral in the cell membrane. This makes the membrane more like of a liquid (fluid) than solid.
2. it is termed as mosaic because similar to a mosaic, it is composed of irregular shapes and structures of proteins, fats, phospholipids, glycoproteins, cholesterol, lipoproteins, etc. These structures tend to be visualized as patches of colors similar to a mosaic art.