To break things down a bit, cloud VPS (Virtual Private Server) hosting is when a web hosting provider takes one massive server and partitions it up so that it can have several servers on it, each of which can run its own operating system and can be re-booted independently.  Sounds simple enough.  So what is the difference between managed VPS and unmanaged VPS?

Use Virtual Network to build your services that rely on Azure cloud services and Azure Virtual Machines. Use Azure web roles for your front end and virtual machines for backend databases. Combine platform as a service (PaaS) and infrastructure as a service (IaaS) in a virtual network to get more flexibility and scalability when you’re building apps.

A VPS Server is the reasonable web hosting choice for your domains when more system resources are needed. VPS takes of the virtualization technologies to partition physical servers into several virtual machines. Virtual Private Server Hosting is the future of modern hosting as it provides the power and functionality of a high-end dedicated server but at a much lower price. Main virtualization technologies used including Vmware, OpenVZ and XEN etc. By purchasing a VPS hosting package, you get a 100% individual machine with your own dedicated CPU and RAM, and mostly root access to the hosting server. Each Virtual Server can run under its own operating system (Windows server, CentOS and other Linux distributions) or have custom configurations of its own.
A VPS hosting provider relies on virtualization software, called a hypervisor, to abstract resources on a physical server and provide customers with access to an emulated server, called a virtual machine (VM). Each virtual machine runs a complete operating system, and has restricted access to a portion of the physical server's compute, memory and storage resources. Customers have access to the VM's OS, but not to the physical server.

With our dedicated servers, you rent an entire server. This is optimal for people that have very high traffic to their websites or need to setup their server in a very specific way. Not everyone needs to have a fully dedicated web server however. If you're just getting started with your website, you can save quite a bit of money if you rent a small portion of the server. Shared hosting is when you share a portion of the server with other users rather than rent an entire server to yourself.

It’s recommended that you do not statically assign the private IP assigned to the Azure virtual machine within the operating system of a VM, unless necessary, such as when assigning multiple IP addresses to a Windows VM. If you do manually set the private IP address within the operating system, ensure that it is the same address as the private IP address assigned to the Azure network interface, or you can lose connectivity to the virtual machine. Learn more about private IP address settings. You should never manually assign the public IP address assigned to an Azure virtual machine within the virtual machine's operating system.
Partitioning a single server to appear as multiple servers has been increasingly common on microcomputers since the launch of VMware ESX Server in 2001. The physical server typically runs a hypervisor which is tasked with creating, releasing, and managing the resources of "guest" operating systems, or virtual machines. These guest operating systems are allocated a share of resources of the physical server, typically in a manner in which the guest is not aware of any other physical resources save for those allocated to it by the hypervisor. As a VPS runs its own copy of its operating system, customers have superuser-level access to that operating system instance, and can install almost any software that runs on the OS; however, due to the number of virtualization clients typically running on a single machine, a VPS generally has limited processor time, RAM, and disk space.[2]