OTRS::ITSM Clarification request

[z000575]

Hello,
I need few more clarifications on the admin settings, please find my queries as follows;

a. What is General Catalogue? How this will be helpful in managing the request?
b. What is State Machine? It’s usefulness in managing the request?
c. what is the difference between State Machine & Status; how both are used in the tool for managing the request?
d. How can I map a different workflow (State Machine) for a type of incident, request, service etc.,
e. How could I create a new state machine?
f. How do I link a State machine with a role/user/group?

Regards,
Ramesh Mandadi