Integral- Pass through both phospholipid layers, direct path from inside to outside the cell (Transport things that cannot diffuse through the membrane)
Peripheral- Free on membrane surface or embedded to the inner or outter surface of the membrane, may even be bound to integral proteins (extracellular peripherals may be cell recognition receptors or even Glycoproteins. Cystolic peripherals can dissociate from the membrane and move into cytoplasm for cell signalling and chemical reactions)
Glycoproteins- proteins with a carbohydrate chain attached
