What is VPS?

As a result of efforts of various software companies and developers offering this service, several names were established for the same technology:

  1. VPS - Virtual Private Server
  2. VDS - Virtual Dedicated Server
  3. DDS - Dynamic Dedicated Server

What is VPS after all?

Long story short, VPS stands for splitting one physical server to multiple separate independent virtual servers.
Both Unix and Windows systems can be split. As a result of separation, a few standalone dedicated servers are formed, while still being physically located on one server.
Each VPS has its own operating system distribution kit, in which it is granted practically unlimited rights of super-user. This means having root (UID: 0) level rights under Unix or Administrator account under Windows, which allows compiling or installing specific software with specific configuration.

VPS advantages
Each VPS can have one or more IP addresses, through which inbound and unbound traffic goes. Even if one VPS happens to be under DDoS attack, other ones won’t be affected (it’s worth to mention that other VPS can still be affected, but due to secondary reasons, for example in case the server’s shared channel is not broad enough and attacking packages fill it up completely).
VPS guarantees that minimum resource consumption will be observed. Client will never face accusations considering excessive usage of CPU or memory resources, which often happens on regular virtual hosting providers.

Quick reboot of virtual server, opportunity to back up VPS by taking a snapshot of the entire system.

Increased stability of operation for lower expense.

Virtual private server is suitable for projects having a high visitor count, but not requiring large portions of memory and CPU resources constantly. VPS enjoys the greatest popularity among companies’ official websites and online shops.
There are several mainstream VPS-hosting technologies: Xen, VMware, Virtuozzo.

Xen and VMware technologies allow creating a virtual environment, which completely imitates physical server operation. This excludes a possibility of one server interfering with another, regardless of consumed resources portions. Besides, Xen and VMware technologies provide support for almost any operating system.

Virtuozzo technology allows distributing physical server resources within one or another operating system. The main difference of this technology from latter two is that it can provide clients with a greater amount of resources than actual server has. This allowance relies on the fact that the entire server resources are not likely to be demanded simultaneously. Therefore, this service is practically identical to a regular virtual hosting. Virtuozzo technology does not provide isolation of virtual servers one from another, which means that resource-heavy virtual machines may interrupt operation of other clients’ servers.