How HTTPS certificates are checked
A browser checks a website certificate to confirm that a trusted authority has linked a public key to the domain. The certificate does not make the site honest,…
Read the guide →Internet
<p>The protocols, services and habits behind the web.</p>
How email delivery works
Email moves through several systems. A sending client submits a message to a mail server, which looks up the recipient domain’s mail records and transfers the message to…
Read the guide →How DNS works when you open a website
DNS is the directory system that turns a human-friendly domain name into an IP address a network can use. When you type a URL, your browser first checks…
Read the guide →VPN explained: what it protects and what it does not
A virtual private network creates an encrypted connection between your device and a VPN server. Your internet provider sees a connection to that server rather than every destination,…
Read the guide →HTTP and HTTPS: what changes when a site is secure
HTTP is the protocol browsers use to request and receive web resources. HTTPS is HTTP carried through a TLS-encrypted connection. TLS helps prevent people on the network from…
Read the guide →How search engines discover and rank pages
Search engines generally work in three stages: crawling pages, indexing what they find and ranking results for a query. Crawlers follow links and read sitemaps, the index stores…
Read the guide →IP addresses, ports and the shape of a connection
An IP address identifies an interface on a network so packets can reach it. Private addresses work inside a local network, while public addresses are reachable through the…
Read the guide →Cookies, sessions and why websites remember you
A cookie is a small piece of data a website asks a browser to store and send back on later requests. Sites use cookies for preferences, login sessions,…
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