(Q) Understanding Real Terms of CPU virtualization?

Hi Team.

I need to understand the real terms of CPU virtualization in ESX / ESXi solution. In clear text:

1. If a virual machine runs on 2 or 4 logical CPUs, how many of physical CPUs it utilizes on physical host.

2. How the concept of logical CPU works.

3. How to measure the real time CPU virtualization performance and a single state CPU performance monitoring on a VM.

P.S. Just to update it say, host physical machine has 8 CPUs total (Xeon) and VM has 4 virtual processors.

I would appreciate if someone can reply with answers in "clear text" terms. Thanks a ton.

Warm regards,

Anshul