VMWare offerings here can be split into four categories:-
ESXi hypervisor – bare metal hypervisor, like Citrix XenServer. This is VMware’s loss leader; VMware gives it out for free, while making most of its revenue on augmenting ESXi functionality with vSphere bundles.
vSphere – vSphere is essentially a commercial offering of ESXi which includes the hypervisor and a set of enterprise stuff, such as tools for live migration, advanced security, network and storage I/O control etc.
vCenter – To run vCenter the user should also purchase some vSphere bundle. In addition to vCenter Server, VMware offers vCenter plug-in modules such as Recovery Manager, Lab Manager (to manage DevOps environments), Chargeback etc.
Layer 4: vCloud Director – if you want to take your VMware-based virtualized datacenter and turn it into an IaaS-like service, this is what a user should use. Key features include externally facing self-service functions such as an infrastructure services catalog,