Actually when you have a dedicated server, you have all hardware resources allocated to your server. Inside this one, you can create several virtual servers called VPS (Virtual Private Servers or Virtual machines). To be able to achieve that point, you need to use virtualization. And there are several technologies to perform that. For linux, you have openvz, kvm, lxd, xen, virtual box for example. Then for windows, you have Vmware, Hyper-V.
As said by daniel , having a server with WHM can help you cut multiple plans with c-panel already in. You can create multiple VPS from a whole dedicated server , the resources allocation is at your will.
To create a VPS from Dedicated server is most important task for all VPS resellers which can be done by using following things.
a) You may add multiple domain if you have Cpanel/WHM with you mostly used in shared hosting
b) You may setup of Hypervisor on the dedicated server
c) Openvz for linux (Virtualization) is the best way to create a VPS for linux or what you called is partition and for windows you may use Vmware or Hyper V
A bit late to reply, but I will try to give my 2 cents.
You can use a dedicated server to create VPS-es, but what type of VPS-es and how, will be decided by your dedicated server specifications.
Now, since you asked about plugins, here are a few more famous choices: Proxmox VE, Virtualizor, SolusVM. If you want to get a more detailed answer, you will need to list your dedicated server specifications.