Root server

A root server (or dedicated server) is your own machine inside the data centre: no hypervisor between you and the hardware, no shared CPU slices, no noisy-neighbour effect. You get root access via SSH or iLO/IPMI, install the operating system directly on bare metal and decide the RAID layout, firewall and networking yourself. Advantages: maximum, stable performance and full data sovereignty (often with a dedicated IPv4 block). Drawbacks: longer minimum contracts (usually one month, no hourly billing), no elastic scaling and higher entry prices. The right pick when sustained high load is expected (database replicas, video encoding, game servers, large mail servers) or when compliance rules forbid sharing hardware with other customers.