There are various kinds of servers; everything out of email servers, web servers and proxy servers into wow private server and backup servers.
Virtual Servers are a hybrid of a dedicated server; one that is stand-alone and is ordinarily used for one high traffic site, plus a shared hosting kind where many websites are hosted on a single platform.
There are many advantages to using virtual servers vs. shared hosting or dedicated servers.
At a shared hosting arrangement, if the server software becomes corrupted or if one particular host site becomes corrupt it may knock each of the other hosted sites offline. You can browse https://intergrid.com.au/virtual.php to know more about virtual servers.
One benefit, however, is that it is the most cost-effective at the host installations as a result of shared hardware resources.
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On the other side, the scalability of a dedicated server may cause problems if expansion is necessary.
In cases like this, the site would need to be offline unless it was ported to a completely different server and while more reliable than a shared hosting setup it is also much more expensive.
The physical server is split into many virtual servers each running completely independent from one another. If one of the virtual servers goes down, the others on the physical server are not affected.
The VPS concept allows the customer to conduct a comprehensive server installation with guaranteed resources while at the same time sharing the physical server. This decreases the cost of the customer.