A Virtual Server is a product where for a set monthly fee, you hire a slice of our Virtual Server infrastructure. Your virtual server runs its own operating system (such as Windows or Linux) that is dedicated to your requirements. With the virtual server you receive a set amount of RAM, Disk Space, Network Bandwidth and CPU resources that allow you to run that operating system and any other programs you wish to run on it. For example you could run Linux with Apache and MYSQL to allow you to run your PHP based website. Or you could run Windows, MSSQL and ASP.NET to host an ASP.NET website.
One of the main advantages of a Virtual server is that the entry cost is much lower than a dedicated server and you have the ability to expand the server resources as your requirements grow.