The ultimate in customized hosting is the dedicated server. Special websites that need high processing power (data processing/large databases), need high bandwidth (streaming video), large secured storage (large and/or many files) and/or special applications (game server) are just some examples of requiring a dedicated server.
A dedicated server is something that requires a whole lot of planning in advance just like planning a building. All aspects have to be considered from processing power, memory, storage all the way to what OS and software that will be installed.
Note: Dedicated server packages are somewhat scalable. Which means if you need more or less storage space/memory those changes can be made. However requires physically making those changes by adding/removing hardware.
Just like all the other hosting plans you can have WebTerritory do software installs, add SSL, even configure and do maintenance for you. However only if your server configuration meets the minimum requirements.