VMWare server vs ESXi - what't the difference?

Question

I can't figure out what is the difference between these two programs. Specifically, I'm interested in running a virtual server in the background, as a daemon (Linux host OS)

Answer 1

VMware Server runs as an application on a normal OS Windows or Linux. ESXi installs it's own hypervisor as the base OS.

If you're asking about this, then it's likely that you should start out with VMware Server.

Answer 2

from the VMware website, Server is a hosted application, ie it runs inside a host OS. ESX runs on the baremetal.

Answer 3

Just like these guys have mentioned. ESXi is free though. Not expensive as previously stated.