The model(fluid mosaic model)is used to explain the structure and the function of the cell membrane. For e.g, the bilipid layer of the membrane, which are the hydrophilic- the head(water loving) and the hydrophobic- the tails(water haters)...
This model basically expalins all stuff about the membrane, not much info to give but u can check it out in some bio websites... it's pretty cool stuff.