What are the technical differences and similarities between VoIP and IP Telephony?

Besides the obvious differences, what are the best practices for migrating to either of these voice technologies?
What are the primary drivers for chossing one over the other?
How can distributed mobile, telecommuting, and office voice technologies be managed.
Is hardware device standardization imperative for effective management practices?
What are the applications?

 out of  found this valuable. Do you find this valuable?