How Spam Filters Work
Learn how spam filters work: they score content, reputation and authentication, then act on the total. Covers rules, machine learning and false positives.
Knowledgebase
Clear answers to common hosting questions, written by our editors.
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By Maarten Soetens
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Full vs Paravirtualization
Paravirtualization uses guest-aware drivers, while full virtualization emulates complete hardware. Learn the trade-offs and how modern hypervisors combine both.
By Maarten Soetens
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Hosting Control Panels Explained
A hosting control panel is a browser-based tool for managing websites, email, databases and files without typing commands. Here is what it does.
By Maarten Soetens
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Parts of a Domain Name
Learn the parts of a domain name, from the TLD and second-level name to subdomains and the www question, and how each label is read from right to left.
By Maarten Soetens
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What Is ZFS?
ZFS is a file system and volume manager with pooled storage, copy-on-write, checksums and snapshots. Learn how ZFS works and why storage servers use it.
By Maarten Soetens
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Domain Control Validation
Domain control validation explained: how email, HTTP and DNS methods prove you control a domain, and why DNS validation is needed for wildcard certificates.
By Maarten Soetens
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IDS vs IPS Explained
An intrusion detection system (IDS) watches traffic or systems for signs of attack and raises alerts. An IPS can also block them. Learn the difference.
By Maarten Soetens
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SPF vs DKIM vs DMARC
SPF DKIM DMARC are the email authentication standards that block forged senders. See what each checks, where each falls short and why all three matter.
By Maarten Soetens
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Unix vs Linux
Unix vs Linux: Unix is the older family of operating systems that inspired Linux. Learn their history, POSIX compatibility and licensing differences.
By Maarten Soetens
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Certificate Authorities
What is a certificate authority? Learn how CAs verify domain owners, sign certificates, why browsers trust them and what happens when a CA loses that trust.
By Maarten Soetens
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ALIAS, ANAME and Flattening
A DNS alias record lets a bare domain point to a hostname, using ALIAS, ANAME or CNAME flattening. Learn how each works and what trade-offs to expect.
By Maarten Soetens
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Database Indexes
A database index helps queries find rows faster. Learn how B-tree indexes work, how clustered and non-clustered indexes differ, and what they cost.
By Maarten Soetens