What Is an IP Address?
Learn how IP addresses route Internet traffic, how IPv4 and IPv6 differ, what NAT does, and what an IP address can and cannot identify.
Read What Is an IP Address?Evergreen technical guides
Learn How the Web Works
Understand the systems behind the diagnostic results: addressing, DNS, email authentication, HTTPS, headers, redirects and browser privacy.
How IP Geolocation Works
Understand how IP geolocation databases estimate country, region and city, why providers disagree, and why the result is not GPS location.
Read How IP Geolocation WorksDNS Record Types Explained
A practical guide to DNS resolvers, A, AAAA, CNAME, MX, TXT, NS, SOA, PTR records and TTL values with clear examples.
Read DNS Record Types ExplainedDNSSEC Explained
Learn how DNSSEC authenticates DNS data with signatures, DNSKEY and DS records, what the chain of trust means, and what DNSSEC does not do.
Read DNSSEC ExplainedSPF, DKIM and DMARC Explained
Understand the distinct roles of SPF, DKIM and DMARC, how their DNS records work together, and why they do not guarantee email delivery.
Read SPF, DKIM and DMARC ExplainedHTTPS and TLS Certificates Explained
Learn how HTTPS, TLS certificates, certificate authorities, hostname validation, SAN, SNI and expiration work together.
Read HTTPS and TLS Certificates ExplainedHTTP Headers Explained
A clear guide to HTTP request and response headers, content type, caching, compression, CSP, HSTS and referrer policy.
Read HTTP Headers ExplainedBrowser Fingerprinting Explained
Learn how browser attributes, WebGL and canvas may contribute to a fingerprint, how normalization helps, and how fingerprints differ from cookies.
Read Browser Fingerprinting ExplainedHTTP Redirects Explained
Understand HTTP redirect status codes, method handling, redirect chains, HTTPS upgrades, loops and practical user-experience implications.
Read HTTP Redirects ExplainedUse a guide with a live diagnostic
Each guide links to focused WhatWebSees tools, and tool results link back to the concepts that explain them. These are reference articles rather than news posts: they emphasize stable protocol behavior, practical examples, limitations and careful interpretation.
Looking for a concise definition? Browse the single-page web, network and privacy glossary.