A record
A DNS record that maps a hostname to an IPv4 address. IPv6 addresses use AAAA records instead.
DNS & networking
KNOWLEDGE AT A GLANCE
Small terms.
Big questions?
From DNS to backups: find short explanations of the terms used in our articles. Search directly or browse by topic.
Explore the PTR guide →24 terms · Page 1 of 2
Backup
A separate copy of data used for recovery after loss or damage. Its usefulness depends on retention, separation from the original and tested restoration.
Backup & operations
CGNAT
An internet-provider technique that lets several customers share a public IPv4 address. This can restrict incoming connections and control over the public address.
DNS & networking
DKIM
Adds a cryptographic signature to email. Receiving servers use a public DNS key to check the signature and identify the signing domain.
Email · Security
Read the full guide: DKIM →DMARC
Checks whether a successful SPF or DKIM result aligns with the visible From domain. The domain owner can publish a handling policy and request reports.
Email · Security
Read the full guide: DMARC →DNS
The Domain Name System connects domain names with technical information such as IP addresses and mail server destinations. Different record types serve different purposes.
DNS & networking
DSM
Synology's operating system for its NAS devices. It provides the administration interface and manages installed packages and services.
Synology
HTTPS
HTTP transported over a TLS-encrypted connection. It protects web traffic between the browser and the server.
Security
IMAP
A protocol for accessing email stored on a server. Messages and folders can be synchronised across several devices.
IP reputation
An assessment of an IP address based on observed sending behaviour and other signals. Poor reputation can affect email acceptance or spam classification.
Monitoring
Regular observation of systems and services to detect failures, unusual behaviour or resource limits and trigger a response.
Backup & operations
MX record
A DNS record identifying the mail servers that accept incoming email for a domain. It points to a hostname and includes a priority.
DNS & networking · Email