18 terms

VPS terms in plain English

Round-trip time (RTT): The time a packet needs to travel to a server and back, measured in milliseconds. Distance sets the floor: light in fibre covers about 100 km per millisecond round trip, and real routes are rarely straight.
Data-center city: The metro area where a host rents rack space. Two suburbs of the same metro count as one city here, so a host with Ashburn and Reston counts once.
KVM: A Linux virtualization layer that gives each VPS its own kernel and reserved memory. It is the default for modern VPS and allows custom ISOs and Windows.
vCPU: One virtual processor thread given to a VPS. Shared vCPUs are time-sliced with neighbours; dedicated ones are pinned to a physical thread.
Dedicated CPU: A plan type in which cores are reserved for one customer. Costs more, but speed does not change with other tenants’ load.
NVMe storage: Solid-state disks attached over PCIe. Random reads and writes are several times quicker than on SATA SSD.
Unmetered traffic: No monthly transfer cap. Speed is limited by the port and a fair-use rule instead.
DDoS filtering: Upstream scrubbing of attack traffic. Capacity and layer-7 coverage vary and are seldom published.
Snapshot: A saved image of a server disk you can restore or clone. A snapshot is not a remote backup: it usually lives in the same facility.
Anycast: One IP announced from many cities so users reach the closest. Common for DNS and CDN, rare for ordinary VPS.
BYOIP: Bringing your own IP block to a host and announcing it there. Needed for portable addresses and BGP setups.
Egress fee: A charge for data leaving the provider’s network. Hyperscalers bill it per GB; most budget hosts bundle a transfer allowance.
IPv6-only plan: A cheaper tier that ships without a public IPv4 address. Fine for servers fronted by a proxy, awkward for direct visitors on older networks.
Hourly billing: Charges accrue per hour of existence, capped at a monthly price, so short-lived servers cost cents.
Uptime SLA: A written promise of availability, normally paid in service credit when missed. Credits are rarely worth the lost revenue.
Account verification: Identity or payment checks some hosts run before activating a server. Policies differ and change; read the signup flow.
Peering: Direct links between networks that shorten routes. Cities with large exchanges, such as Frankfurt or Amsterdam, often give lower real latency than distance suggests.
Latency estimate: On this site: 5 ms plus distance divided by 59 km per ms, measured from the largest city of the audience country to the nearest data-center city. Treat it as a floor-plus-allowance, then test with a trial.