What are the classifications of membrane proteins based on their different characteristics?

There are two ways membrane proteins can be classified based on their different characteristics. 

Based on duration of membrane association, membrane proteins can be classified as:

• Integral membrane proteins, which are firmly and permanently attached to the lipid bilayer
• Peripheral membrane proteins, which are loosely and temporarily attached to the membrane or to integral membrane proteins

Based on mode of membrane association, membrane proteins can be classified as: 

• Transmembrane proteins, or bitopic proteins, which cross the membrane layer at least once
• Monotopic membrane proteins, which are attached to one side of the lipid bilayer and can interact with the membrane in different ways