What are the different layers of OSI model in networking?

Question

It is generally said that BGP protocol belongs to Application Layer of OSI model but how is this possible ?

It is made use of by border routers which belongs to level-3 then will that mean border routers are special kind of routers which act at application layer?

How do they differ from general routers?

Answer 1

Physical (Layer 1)
Data Link (Layer 2)
Network (Layer 3)
Transport (Layer 4)
Session (Layer 5)
Presentation (Layer 6)
Application (Layer 7)