The Introduction of Shared, VPS, Dedicated
Shared
– Sharing a server with lots of other people. Virtual hosting. All the domain names are shared by the server and they all share the same IP (not always, you can still host multiple IPs off of one box).
Cheapest solution and good for most people. Sometimes shell accounts are given which use CHOWN or windows permissions to emulate some sort of freedom. We call this in the industry “SSH Jail”
VPS
– Usually only a few partitions are on this server and 1 user per partition in which they have root/superadmin access. You can’t usually reboot the machine, but you can add pretty much what you want and run what you want as long as too much memory and CPU isn’t used. Good for high traffic sites and/or devs.
Self Managed Dedicated
– Your own server you rent. You are the root/superadmin. And as long as its within the provider’s TOS you can do it. But you are on your own with everything minus the base install. Good for game servers.
Managed Dedicated
– Your own server you rent. You are the root/superadmin. And as long as its within the provider’s TOS you can do it. Tech support is included in your monthly rental usually. And if you don’t want to do it, then you usually can just tell them to. Its like getting a Dedicated Server and then having an IT team…almost anyway. Good for corporations and high traffic sites.
On the other hands, I tried to be very detailed and cut some things out that quite useful so it wouldn’t be longer to read.
Well there isn’t res all the things (PHP, ASP, CGI, whatever) installed on both so that you can do that. MySQL is usually used on both windows and linux machines now. For shared hosting its mostly just preference, not that you can tell much of a difference between them from the webhosting user level.