A visual guide to web technology
The web, clearly
explained.
Understand hosting, domains, networks, and the technology behind every website.
A few ideas to start with.
Browse the library- concept
URL structure
Read a web address, one part at a time. Learn what reaches the server—and why the fragment is different.
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Latency vs bandwidth
Waiting is not the same as transferring. See how round-trip time, body size and goodput shape one simplified response.
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DNS TTL
A DNS answer can outlive a change at its source. Follow one resolver cache—not a global propagation clock.
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Web hosting
See what a hosting environment supplies, trace a static or dynamic request, and separate service capabilities from the responsibilities in your plan.
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Domain name
A domain names a place in DNS. It is neither the complete URL nor the site files or hosting account.
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Domain vs hosting
Separate registration, DNS, website hosting and mail, then explore what changes—and what stays unchanged—when you renew a domain or prepare a new host.
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Shared hosting vs VPS
Shared hosting simplifies administration; a VPS offers more system control. Neither guarantees speed or reliability.
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Managed vs unmanaged hosting
“Managed” describes which jobs a provider performs, not whether the machine is shared, virtual or dedicated.
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VPS vs dedicated server
Compare shared-host VMs, sole-tenant VMs and bare metal by physical exclusivity, hardware access, resizing and operational responsibility—not a universal score.
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Static vs dynamic website
Static pages can still be interactive. The key distinction is when and where HTML is produced for a request.
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Choose hosting for a small website
A practical selection checklist for a small site: requirements, responsibility, verification and an exit plan.
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Connect a domain to a website
Connect web DNS safely without disrupting existing mail: check delegation, stage the site, change only needed records and verify.
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DNS resolution
Trace cold and cached DNS lookups, distinguish referrals from answers, and see why NXDOMAIN, NODATA and an HTTP response are different outcomes.
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Authoritative nameserver
Learn how authoritative nameservers answer for DNS zones and why registrar delegation must point to the zone you edit.
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Recursive DNS resolver
Understand recursive DNS resolvers, cache hits and misses, negative caching, and why cached data is not a global clock.
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DNS A and AAAA records
Compare DNS A and AAAA records by address family, check both sets independently and avoid assuming IPv6 always works.
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CNAME record
See how a DNS CNAME aliases a hostname to another name and why ordinary records cannot share that alias owner.
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MX record
Understand MX targets and lower-number mail preference, independent of website A/AAAA records and mail authentication TXT.
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Change a DNS record safely
Rehearse a single web A-record change, inspect the protected zone data, compare two resolver caches and practice a rollback that does not erase cached answers.
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A DNS change is not visible
Diagnose an invisible DNS change by separating wrong-zone edits, delegation, cached positive or negative answers, and record type.
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A website works for some visitors only
Isolate why a site works for some visitors but not others using DNS, IPv4/IPv6, TLS, caches and origin checks.
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HTTP request and response
Read the method, target, headers, optional body, status and returned content in a small HTTP exchange.
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HTTPS and TLS
Understand what HTTPS protects with TLS, how a browser authenticates a service, and which threats remain.
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Reverse proxy
See how a reverse proxy receives public requests and forwards them to one or more upstream applications.
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CDN
Understand how a CDN serves nearby edge responses, when it contacts origin, and why not all content is cached.
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Browser cache
Learn when a browser can reuse a response, revalidate it, or must fetch it again under HTTP caching rules.
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HTTP 404 troubleshooting
Diagnose an HTTP 404 from request, deployment, routing and cache evidence, then test a narrow correction without turning genuinely missing routes into success pages.
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HTTP 502 troubleshooting
Investigate a proxy 502 by separating upstream response failures from 404, 503 and 504 without risky restarts.
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Back up a small website
Plan a recoverable small-site backup that includes deployable source, configuration, changing data and a tested restore.
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SSH vs SFTP
Compare SSH remote command sessions with SFTP file transfers carried over SSH, including their security limits.
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DNS TXT record
A DNS TXT record holds textual data at a DNS owner name.
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DNS NS records and delegation
An NS delegation tells a resolver which authoritative servers are responsible for a child DNS zone.
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DNS SOA record
The SOA (Start of Authority) record identifies administrative parameters for a DNS zone.
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DNSSEC
DNSSEC lets a validating DNS resolver authenticate signed DNS RRsets through a chain of trust.
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DNS CAA record
A DNS CAA (Certification Authority Authorization) RRset expresses which certificate authorities may issue specified certificates for a domain.
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SPF email authentication
SPF (Sender Policy Framework) lets a receiving mail system evaluate whether an observed SMTP sending IP is authorized for a specific SMTP identity, commonly MAIL FROM or HELO.
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DKIM email signatures
DKIM (DomainKeys Identified Mail) associates a signing domain with selected canonicalized email headers and message content through a cryptographic signature.
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DMARC alignment and policy
DMARC checks whether either SPF or DKIM passes and aligns with the domain in the visible From header; its published policy requests, but does not guarantee, how failures are handled.
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HTTP status codes
An HTTP status code is a three-digit field in a server's HTTP response.
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HTTP redirects
An HTTP redirect is a response directing a client to another URI, usually through a `Location` header and a 3xx status.
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HTTP cookies
An HTTP cookie is a small name/value state item delivered in `Set-Cookie` and potentially returned in later `Cookie` request headers.
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HTTP Cache-Control
The HTTP Cache-Control response field describes constraints on storage and reuse of a response.
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ETag and conditional requests
An HTTP ETag is an opaque representation validator.
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TLS certificates and trust chains
A TLS certificate chain lets a client build a candidate trust path from the service's leaf certificate through one or more issuing intermediates to a configured trust anchor.
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TLS certificate hostname mismatch
A TLS hostname mismatch occurs when the requested reference identity does not match a supported name in the certificate presented by the server.
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IP addresses
An IP address is a network-layer identifier used to deliver packets to an interface or endpoint context.
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TCP vs UDP
TCP provides an ordered, reliable *byte-stream service* under its protocol conditions, using sequence information, acknowledgments and retransmission.
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Network ports
A network port helps identify a transport endpoint within a host's protocol stack.
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CIDR and subnet masks
CIDR combines an IP address and prefix length, such as `192.0.2.0/24`, to describe a range of IP addresses by their leading bits.
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Connection refused vs timeout
Connection refused and connection timed out describe different observations before an HTTP response is necessarily available.
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Follow your curiosity.
A clear definition. A small example to explore. A closer look at why it works.