Where can I learn fundamentals about hypervisors in context of other hardware virtualization solutions? [closed]
This question isn't really on topic here, but ill throw you a bone before it gets closed. I assume by ESX you mean ESXi or the vSphere suite of products. ESX is end of life.
I recommend that you visit technet and VMWare online training as a start. Then pick up some books or have your employer send you to training.
I recommend Mastering VMWare vSphere 5 by Scott Lowe to anyone wanting to learn the ins-and-outs of vSphere.
Also, set up both in a test lab.