Web Hosting Terminology Explained in Plain Language

Server and account terms

Uptime — the percentage of time your server is reachable. A 99.9% SLA allows roughly 43 minutes of downtime per month; 99.99% allows about 4 minutes.
Bandwidth — the volume of data transferred to visitors per month. Text pages use very little; video and large images dominate it.
Inodes — the number of files and folders in your account. Thousands of tiny cache files can hit an inode limit long before a storage limit.
CPU / RAM / I/O limits — how much processing power, memory and disk throughput your account may use at once. Exceeding them causes slow pages or 508 errors rather than an outage.
Root access — administrator-level control of the operating system, available on VPS and dedicated servers only.

Domain and DNS terms

TLD — the domain ending, such as .com, .net, .ai or .com.lb.
Nameserver — the authoritative server that answers DNS questions for your domain.
A record — maps a hostname to an IPv4 address. AAAA does the same for IPv6.
CNAME — points one hostname at another hostname.
MX record — tells the world which mail server accepts email for your domain.
TTL — how long resolvers may cache a record before checking again, in seconds.
WHOIS / privacy — the public registration record for a domain, and the service that masks your personal details in it.
EPP / auth code — the transfer authorisation code required to move a domain between registrars.

Performance and delivery terms

TTFB — time to first byte, a good proxy for server and application speed.
Caching — storing a generated page or query result so the next request is served instantly. Page cache, object cache and OPcache each solve a different layer.
CDN — a global network of edge servers that serve your static assets from a location near each visitor.
LiteSpeed / LSCache — a high-performance web server and its native caching plugin, considerably faster than stock Apache for PHP applications.
Core Web Vitals — Google's user-experience metrics: LCP (loading), INP (responsiveness) and CLS (visual stability).

Security terms

SSL/TLS certificate — encrypts traffic between browser and server and enables HTTPS.
SFTP / SSH — encrypted file transfer and encrypted remote shell access.
WAF — web application firewall, filtering malicious requests before they reach your application.
DDoS mitigation — infrastructure that absorbs floods of traffic intended to knock a site offline.
2FA — a second authentication factor, usually a rotating code from an app.
SPF / DKIM / DMARC — the three DNS-based standards that prove your email is genuine and keep it out of spam folders.

Frequently asked questions

What does 'unlimited' bandwidth actually mean?

It means there is no hard transfer cap under normal website use, but CPU, memory and I/O limits still apply. Genuinely heavy workloads belong on a VPS or dedicated server.

Why is TTFB more useful than page load time?

TTFB isolates server-side performance from front-end weight. A slow TTFB points at hosting, PHP or database work; a fast TTFB with a slow page points at images, scripts and fonts.