ISIS Queries

Hi I am just studying ISIS and there are things I don't understand.
RouterA(config-router)# net 49.0001.0000.0000.000b.00
RouterA(config-router)# hostname dynamic
Is the area id and system id configured statistically or dynamically? Dynamically, how do you "see" what is the correct output?
What is the difference between the clns host and hostname command?
RouterA(config-router)# net 49.0001.0000.0000.000b.00
RouterA(config-router)# hostname dynamic
Is the area id and system id configured statistically or dynamically? Dynamically, how do you "see" what is the correct output?
What is the difference between the clns host and hostname command?
Comments
The area id and system id have been configured statically with the "net" command. 49.0001 is the area; 0000.0000.000b is the system id.
Hostname dynamic maps the hostname to the system id, i.e. RouterA to 0000.0000.000b
clns host refers to the complete net address i.e. 49.0001.0000.0000.000b.00
I am studying here and there for CCIE SP. In fact I got no reference point as to what to study.
So I just ask whatever comes to mind.
As for RouterA becoming 0000.0000.000b, how do you know what it becomes in the first place?