If yes, then this single pager can clear your doubts.
I believe almost everyone in my connections is aware of the OSI model of data communications & that’s why I made a comparative study with OSI so that you can understand better.
An apple to apple comparison will be like as below
ISO ~ ETSI
OSI ~ NFV+MANO
7 layers ~ 3 layers
Just like every layer in OSI has its protocols, applications & rules to coordinate with other layers. Similarly, every layer in NFV+MANO contains its components & rules to coordinate with other layers.