Glossary

• Domains and Registration
• DNS and Records
• Email and Deliverability
• SSL/TLS and Security
• Hosting and Infrastructure
• SEO and Search Optimization

Domains and Registration

• Domain Name
  
• Top-Level Domain (TLD)
  
• gTLD
  
• ccTLD
  
• sTLD (Sponsored TLD)
  
• Brand TLD (.BRAND)
  
• IDN Domain
  
• Punycode
  
• Second-Level Domain (SLD)
  
• Third-Level Domain
  
• Subdomain
  
• Apex Domain
  
• FQDN
  
• Hostname
  
• Registrar
  
• Registry
  
• Registrant
  
• Administrative Contact
  
• Technical Contact
  
• Billing Contact
  
• WHOIS
  
• RDAP
  
• WHOIS Privacy / Domain Privacy
  
• Redacted WHOIS
  
• EPP
  
• EPP Code / AuthInfo
  
• Domain Lock / Registrar Lock
  
• Registry Lock
  
• Domain Transfer
  
• Incoming Transfer
  
• Outgoing Transfer
  
• Push / Internal Transfer
  
• Change of Registrant
  
• Domain Renewal
  
• Auto-Renew
  
• Grace Period
  
• Add Grace Period
  
• Renewal Grace Period
  
• Redemption Period
  
• RGP (Redemption Grace Period)
  
• Pending Delete
  
• Domain Expiration
  
• Expiry Date
  
• Creation Date
  
• EPP Status Codes
  
• clientTransferProhibited
  
• clientUpdateProhibited
  
• clientDeleteProhibited
  
• clientRenewProhibited
  
• serverTransferProhibited
  
• Domain Parking
  
• Domain Forwarding
  
• URL Forwarding
  
• Masked Forwarding
  
• Email Forwarding
  
• Domain Alias
  
• Site Mirror
  
• Canonical Domain
  
• Premium Domain
  
• Reserved Name
  
• Blocked Name
  
• Sunrise Period
  
• Landrush
  
• General Availability (GA)
  
• Trademark Claims
  
• Trademark Clearinghouse (TMCH)
  
• UDRP
  
• URS
  
• Cybersquatting
  
• Typosquatting
  
• Brand Protection
  
• Domain Portfolio
  
• Domain Investor
  
• Domain Flipping
  
• Domain Appraisal
  
• Secondary Market
  
• Domain Auction
  
• Backorder
  
• Drop-Catching
  
• Zone File Access
  
• Thin Registry
  
• Thick Registry
  
• DNS Hosting
  
• Managed DNS
  
• Nameserver Delegation
  
• Registrar Accreditation
  
• ICANN
  
• IANA
  

DNS and Records

• DNS
  
• DNS Resolver
  
• Recursive Resolver
  
• Authoritative DNS
  
• Root Servers
  
• TLD Servers
  
• Anycast DNS
  
• DNS Zone
  
• Zone File
  
• SOA Record
  
• Serial Number (SOA Serial)
  
• Refresh (SOA)
  
• Retry (SOA)
  
• Expire (SOA)
  
• Minimum TTL
  
• TTL
  
• DNS Cache
  
• DNS Propagation
  
• Nameserver (NS)
  
• Glue Records
  
• Delegation
  
• Apex / Root (@)
  
• A Record
  
• AAAA Record
  
• CNAME
  
• ALIAS Record
  
• ANAME Record
  
• MX Record
  
• TXT Record
  
• SRV Record
  
• PTR Record
  
• CAA Record
  
• NAPTR
  
• SSHFP
  
• TLSA (DANE)
  
• NS Mismatch
  
• NXDOMAIN
  
• SERVFAIL
  
• REFUSED
  
• DNS Timeout
  
• Split-Horizon DNS
  
• Split DNS
  
• Wildcard DNS
  
• GeoDNS
  
• Round-Robin DNS
  
• DNSSEC
  
• DS Record
  
• DNSKEY
  
• RRSIG
  
• NSEC
  
• NSEC3
  
• KSK
  
• ZSK
  
• Key Rollover
  
• DS Mismatch
  
• DNS Poisoning
  
• Cache Poisoning
  
• DNS DDoS
  
• DNS Amplification
  
• EDNS0
  
• DNS over HTTPS (DoH)
  
• DNS over TLS (DoT)
  
• Forwarder
  
• Stub Resolver
  
• Resolver Cache Flush
  
• BIND
  
• Unbound
  
• PowerDNS
  
• Knot DNS
  
• Reverse DNS (rDNS)
  
• IP-to-Hostname
  
• SPF DNS Lookup Limit
  
• TXT Record Size Limit
  
• CNAME Flattening
  
• ACME Challenge (DNS-01)
  
• _acme-challenge
  
• _domainkey
  
• _dmarc
  
• _mta-sts
  
• _smtp._tls
  

Email and Deliverability

• Email Deliverability
  
• SMTP
  
• ESMTP
  
• IMAP
  
• POP3
  
• MTA
  
• MUA
  
• MDA
  
• SMTP Relay
  
• SMTP Authentication
  
• STARTTLS
  
• TLS for SMTP
  
• SMTPS (465)
  
• Submission (587)
  
• MX Priority
  
• Catch-All Mailbox
  
• Bounce
  
• Hard Bounce
  
• Soft Bounce
  
• NDR (Non-Delivery Report)
  
• Greylisting
  
• RBL / DNSBL
  
• Spamhaus
  
• Reputation
  
• Sender Reputation
  
• IP Reputation
  
• Domain Reputation
  
• SPF
  
• SPF Include
  
• SPF Redirect
  
• SPF Softfail (~all)
  
• SPF Hardfail (-all)
  
• SPF PermError
  
• SPF TempError
  
• SPF Flattening
  
• DKIM
  
• DKIM Selector
  
• DKIM Key Rotation
  
• DKIM Body Hash
  
• DKIM Fail
  
• DMARC
  
• DMARC Policy
  
• p=none
  
• p=quarantine
  
• p=reject
  
• pct Tag
  
• rua
  
• ruf
  
• fo Tag
  
• adkim / aspf
  
• Alignment
  
• Identifier Alignment
  
• DMARC Aggregate Report
  
• DMARC Forensic Report
  
• ARC (Authenticated Received Chain)
  
• ARC Seal
  
• ARC Fail
  
• BIMI
  
• VMC (Verified Mark Certificate)
  
• MTA-STS
  
• TLS-RPT
  
• DANE for SMTP
  
• SPF/DKIM/DMARC Alignment Fail
  
• HELO / EHLO
  
• Reverse DNS Mismatch
  
• SPF HELO Identity
  
• MIME
  
• DKIM Canonicalization
  
• List-Unsubscribe Header
  
• Feedback Loop (FBL)
  

SSL/TLS and Security

• SSL Certificate
  
• TLS
  
• HTTPS
  
• HTTP
  
• HTTP/2
  
• HTTP/3 (QUIC)
  
• URL
  
• URI
  
• CSR
  
• Private Key
  
• Public Key
  
• Key Pair
  
• RSA
  
• ECDSA
  
• Certificate Chain
  
• Intermediate Certificate
  
• Root Certificate
  
• Certificate Authority (CA)
  
• OCSP
  
• OCSP Stapling
  
• CRL
  
• Revocation
  
• SAN
  
• Wildcard SSL
  
• Multi-Domain SSL
  
• DV SSL
  
• OV SSL
  
• EV SSL
  
• HSTS
  
• Mixed Content
  
• TLS Handshake
  
• Cipher Suite
  
• Perfect Forward Secrecy (PFS)
  
• SNI
  
• ALPN
  
• Session Resumption
  
• 0-RTT
  
• Security Headers
  
• Content-Security-Policy (CSP)
  
• X-Frame-Options
  
• X-Content-Type-Options
  
• Referrer-Policy
  
• Permissions-Policy
  
• SameSite Cookies
  
• CSRF
  
• XSS
  
• SQL Injection
  
• Clickjacking
  
• WAF
  
• DDoS Protection
  
• Rate Limiting
  
• Bot Protection
  
• Malware Scanning
  
• Phishing
  
• DNS Hijacking
  
• MITM
  
• ACME
  
• Let’s Encrypt
  
• Certificate Transparency (CT)
  

Hosting and Infrastructure

• Shared Hosting
  
• VPS
  
• Dedicated Server
  
• Cloud Hosting
  
• CDN
  
• Load Balancing
  
• Uptime
  
• Backup
  
• Snapshot
  
• Control Panel
  
• DirectAdmin
  
• cPanel
  
• SSH
  
• SFTP
  
• FTP
  
• Nginx
  
• Apache
  
• PHP-FPM
  
• Cron
  
• MySQL
  
• PostgreSQL
  
• Caching
  
• WAF
  
• DDoS Protection
  

SEO and Search Optimization

• SEO
  
• Search Engine Results Page (SERP)
  
• Organic Traffic
  
• Keyword
  
• Search Query
  
• Search Intent
  
• Informational Intent
  
• Commercial Intent
  
• Navigational Intent
  
• Transactional Intent
  
• Keyword Clustering
  
• Semantic Core
  
• Topic Cluster
  
• Pillar Page
  
• Entity SEO
  
• Topical Authority
  
• E-E-A-T
  
• CTR (Click-Through Rate)
  
• Title Tag
  
• Meta Description
  
• H1
  
• H2
  
• Alt Text
  
• Internal Linking
  
• Anchor Text
  
• Backlink
  
• Link Equity
  
• PageRank
  
• URL Slug
  
• Friendly URLs
  
• Canonical URL
  
• Duplicate Content
  
• Thin Content
  
• Snippet
  
• Featured Snippet
  
• People Also Ask
  
• Sitelinks
  
• Rich Results
  
• Schema.org
  
• Structured Data
  
• FAQPage Schema
  
• Breadcrumbs Schema
  
• Organization Schema
  
• WebSite Schema
  
• robots.txt
  
• Meta Robots
  
• Noindex
  
• Nofollow
  
• Indexing
  
• Deindex
  
• Crawling
  
• Crawl Budget
  
• XML Sitemap
  
• sitemap.xml
  
• Image Sitemap
  
• News Sitemap
  
• Hreflang
  
• International SEO
  
• Geo-Targeting
  
• Mobile-First Indexing
  
• Responsive Design
  
• Core Web Vitals
  
• LCP
  
• INP
  
• CLS
  
• Page Speed
  
• TTFB
  
• Render-Blocking Resources
  
• Lazy Loading
  
• Pagination SEO
  
• Faceted Navigation
  
• 301 Redirect
  
• 302 Redirect
  
• Redirect Chain
  
• Redirect Loop
  
• 404
  
• Soft 404
  
• 410
  
• 5xx Errors
  
• HTTPS Migration
  
• Site Architecture
  
• Click Depth
  
• Breadcrumbs
  
• JavaScript SEO
  
• SSR (Server-Side Rendering)
  
• CSR (Client-Side Rendering)
  
• Prerendering
  
• Search Console
  
• Index Coverage
  
• Manual Action
  
• Link Spam
  
• Disavow
  
• Branded Traffic
  
• Non-Branded Traffic
  
• Conversion Rate (CR)
  
• SEO A/B Test