what is the difference between a server physical case and a client case
The "Backbone".
Data! Data is usually on servers, so if you're asking what physical component, it would be servers.
virtual hosting
A Cluster Server
"Server Virtualisation can be made to act as many virtual servers, it offers a range of benefits, the most obvious of which is reducing the number of physical servers an organization needs."
Cloud servers are also termed as virtual servers or hosted servers. These are actually not located on any physical location and the best advantage of cloud servers is that, they can be scaled or moved anywhere. And the best part, this transformation doesn't affect the database at all. There are many companies offering cloud servers and other virtual hosting services. Big names like IBM, Amazon, dinCloud are doing a great job in providing cloud services.
You will need physical servers, operating system, switches and backup device.
Virtual Private Servers provide a virtual machine which functions just like a dedicated physical server. They provide lower prices because many virtual private servers can run on a single physical computer when demand is low, and are quite prevalent today.
Unless you blocked yourself in the first place (in which case, do that, but opposite), you don't.
Clustering technoques are implemented for: 1. Load balancing: 2 or more servers work together, but are transparent to the user. So the load balancer, through which the servers are connected, takes care of properly diverting the http request (in case of web servers) to the available server. 2.Failover: In case of a server faliure, other servers take over the request and give the feel of an unhindered service to the user. 3. Scalability: The network size can be increased. A sense of parallel processing comes in as the different servers in the cluster are transparent to the user.
Physical servers (also referred to as boxes) are represented by physically or virtually separate computers with their own operating systems (Linux, FreeBSD Unix, or Windows).
This is dependent on the size of the hard drive(s) located in the server or array of servers. Many larger servers have almost 10 PB of storage. There's no theoretical limit; the major blockers are price and the physical space needed for all the necessary drives.