25 short guides to the questions people ask before renting a server: what a VPS is, how it compares with shared, dedicated and cloud hosting, and what the terms on a plan page mean.
A VPS (virtual private server) is a virtual machine rented on a shared physical server, with its own operating system, root access, IP address and a guaranteed share of RAM and storage. It costs from about $2 to $20 per month for typical plans and sits between shared hosting and a dedicated server.
Shared hosting puts many websites on one server with no root access and no guaranteed resources; a VPS gives you an isolated virtual server with dedicated RAM, root access and your own IP. Switch to a VPS when a site outgrows shared limits, needs custom software or must not be slowed by neighbours.
A VPS is a virtual slice of a physical server with guaranteed RAM and shared CPU; a dedicated server is the whole physical machine. Choose a dedicated server for sustained heavy CPU, large RAM or compliance needs; otherwise a VPS is cheaper and far quicker to scale.
A traditional VPS is a fixed-size virtual server billed monthly; cloud hosting runs the same kind of virtual machine but bills by the hour and lets you create, resize and delete servers through an API. Today most 'cloud VPS' offers combine both.
VDS (virtual dedicated server) is a marketing term, mostly used by European and CIS hosts, for a VPS with dedicated CPU cores. Technically both are virtual machines; check whether the plan actually reserves cores before paying more for 'VDS'.
A VPS is a rented virtual server that can run any software; a VPN is an encrypted tunnel that routes your traffic through another server. You can host your own VPN (WireGuard or OpenVPN) on a VPS to get a private exit IP in the country you choose.
An unmanaged VPS gives you a fresh operating system and root access; updates, security, backups and troubleshooting are your job. A managed VPS adds the provider's administrators, who patch, monitor and support the server, usually with a control panel, for two to five times the price.
KVM (Kernel-based Virtual Machine) is the hypervisor built into the Linux kernel. A KVM VPS runs its own kernel, so it can run Docker, VPNs, custom kernels, Windows and BSD; container systems such as OpenVZ and LXC share the host kernel and are lighter but more limited.
NVMe is a protocol that connects solid-state drives over PCIe instead of the older SATA bus. NVMe drives reach several gigabytes per second and hundreds of thousands of random operations per second, against about 550 MB/s for SATA SSDs, which makes databases, builds and busy sites noticeably faster.
A vCPU is a virtual processor assigned to a VPS, normally one hardware thread of a physical CPU core (two vCPUs per core with hyper-threading). On shared plans vCPUs are time-sliced with other tenants; on dedicated plans they are reserved for you.
In VPS plans, 'bandwidth' usually means the monthly data-transfer allowance (for example 2 TB), while port speed is the maximum throughput at any moment (for example 1 Gbps). Unmetered plans remove the monthly cap but keep the port speed and a fair-use policy.
DDoS protection is network filtering that absorbs denial-of-service floods before they reach your server. Without it, a host usually null-routes an attacked IP to protect other customers, which takes your server offline until the attack ends.
A snapshot is a point-in-time image of a VPS disk that you take manually, usually before a risky change; a backup is an automatic, scheduled copy that rotates and is often stored separately. Both are full-disk images; neither replaces copies kept with another provider.
IPv4 addresses are 32-bit (about 4.3 billion in total) and exhausted, so providers increasingly charge for them; IPv6 addresses are 128-bit and plentiful, and most VPS include a /64 block for free. A dual-stack VPS has both.
An SLA (service level agreement) is the provider's written uptime promise, commonly 99.9% or 99.99% a month, and the service credits it pays when it misses that target. Credits rarely cover the real cost of downtime, so treat the SLA as a signal of how seriously the host engineers availability.
Uptime is the share of time a server or service is reachable, usually quoted monthly as a percentage: 99.9% allows about 43 minutes of downtime a month, 99.95% about 22 minutes and 99.99% about 4 minutes.
Latency is the time a packet takes to travel to a server and back, measured in milliseconds. It is driven mainly by distance: light in fibre covers about 200 km per millisecond, so every 1,000 km between you and your VPS adds at least 10 ms of round-trip time.
Root access is full administrative control of a server's operating system (Administrator on Windows): you can install any software, change any setting and are responsible for security. Every unmanaged VPS includes it; managed platforms such as Cloudways do not.
A VPS control panel is web software that manages websites, databases, email and SSL on your server through a browser. cPanel and Plesk are commercial and licensed per server or account; CloudPanel, HestiaCP, aaPanel and CyberPanel are free.
cPanel is a commercial web-hosting control panel (with WHM for the server administrator) that manages websites, email, databases, DNS and SSL through a browser. On a VPS it is an optional, separately licensed add-on that turns the server into a classic hosting environment.
RDP (Remote Desktop Protocol) is Microsoft's protocol for a full graphical session on a remote Windows computer. It is how you use a Windows VPS: connect with the Remote Desktop client to the server's IP on port 3389 and log in as Administrator.
Custom ISO support lets you boot a VPS from your own installation image, so you can install an operating system the provider does not offer, such as pfSense, a BSD or Windows with your own licence. It requires KVM and a VNC or web console.
Hourly billing charges for a VPS per hour of existence, with a monthly cap at the plan's monthly price (reached after about 730 hours). It makes short-lived servers, tests and CI jobs cost cents.
Securing a VPS comes down to a short list: log in with SSH keys and disable password and root logins, run a firewall that opens only the ports you need, install security updates automatically, add brute-force protection, take backups and keep software minimal.
To set up a VPS: choose a provider, location and Linux image, add your SSH key, connect with ssh root@your-ip, create a sudo user, update the system and enable a firewall, install your stack (a web server, or Docker), point your domain's A record at the server's IP and add a free Let's Encrypt certificate.