You may start reading about UCCE components first (Logger, Router, CVP, CUIC, CTI OS, HDS, Finesse, VXML Gateways etc).
Anyway, below is my view on queries which you have raised.
CVP: Customer Voice Portal provides the IVR and queuing functionalities to callers. IVR functionalities can be provided by any voice portal (e.g. Avaya voice portal also) and voice mail applications also provides little bit functionality of IVR like CUC, CUE, Nortel Call pilot, Avaya MM etc. So we cant compare CVP & IVR with each.
Script editor is used to create scripts for ICM and whereas Call Studio is used to create/develop applications for CVP (once you develop an application then you need to upload it on CVPs). Script editor provide flow editor to create ICM's scripts and Call studio provides two options; one is flow editor and another one is using java.
Below are some videos on Youtube which explains call flow and scripting overview and there you can find more videos as well...just explore :-) https://www.youtube.com/watch?v=p46zEgCetbY
https://www.youtube.com/watch?v=Lj_PW5ZvWBU
Suresh