Networks, Infrastructure & Edge

Internet Protocol address

A numeric identifier used to route network traffic to an interface using IP.

Internet Protocol version 4 / version 6

The two widely used IP versions; IPv6 provides a much larger address space and other protocol changes.

Transmission Control Protocol / User Datagram Protocol

Two transport protocols: TCP provides an ordered reliable byte stream, while UDP sends independent datagrams with less overhead.

A numbered network service endpoint

A transport-layer number that lets one host direct TCP or UDP traffic to the correct application process.

A logical subdivision of an IP network

A range of addresses grouped by a shared network prefix for routing and administration.

Classless Inter-Domain Routing

Notation and routing practice that describes an IP prefix with an address and prefix length, such as /24.

Virtual Private Cloud / Virtual Network

A logically isolated cloud network where addresses, routes, subnets and security controls are configured.

Virtual Private Network

An encrypted or otherwise protected connection that extends network access across an untrusted network.

Network Address Translation

A gateway technique that rewrites IP addresses, commonly allowing private networks to share public addresses.

A control that filters network traffic

Hardware or software that permits or blocks connections using defined rules and observed traffic properties.

Intermediaries for client or server traffic

A forward proxy acts for clients; a reverse proxy receives requests on behalf of servers and may route, secure or cache them.

Transport Layer Security / Secure Sockets Layer

TLS protects data in transit with authentication, integrity and encryption; SSL is its obsolete predecessor but remains common shorthand.

Certificate Authority

A trusted entity that issues and signs digital certificates binding public keys to identities.

Public Key Infrastructure

The roles, policies and technology used to issue, manage, validate and revoke digital certificates and keys.

A human-readable name in the Domain Name System

A hierarchical name such as example.org that DNS can map to records including IP addresses.

A server that answers DNS queries

A DNS server that provides authoritative records or resolves names on behalf of clients.

Processing closer to users or data sources

Running compute and storage near the network edge to reduce delay, bandwidth use or dependency on a central region.

One IP address announced from multiple locations

A routing method that directs traffic to one of several nodes advertising the same address, often the topologically nearest.

Delay between an action and its response

The time data or a request takes to travel and be processed, commonly measured in milliseconds.

Capacity versus achieved transfer rate

Bandwidth is a link's theoretical capacity; throughput is the useful data rate actually achieved.

A machine and the name that identifies it

A host is a networked machine or service; its hostname is the label or domain name used to identify it.

Top name in a DNS zone

The domain name at the top of a DNS zone, before adding host labels such as www or app.

Canonical Name record

A DNS record that makes one domain name an alias of another canonical domain name.

Text record

A DNS record that stores text, commonly used for domain verification and email-security policies.

IPv4 / IPv6 address records

DNS records that map a name to an IPv4 address with A or an IPv6 address with AAAA.

Mail Exchange record

A DNS record that names the mail servers responsible for receiving email for a domain.

Time to Live

A DNS value stating how many seconds a record may remain cached before it should be requested again.

Administrative portion of the DNS namespace

A managed section of DNS containing the records for a domain and any names not delegated elsewhere.

Delay while cached DNS data expires

An informal name for the period in which different resolvers still return old cached records after a DNS change.

Domain Name System Security Extensions

Extensions that let resolvers authenticate DNS data and detect tampering by checking cryptographic signatures.

Domain below another domain

A domain positioned beneath another name in the DNS hierarchy, often used to separate sites, services or environments.

Fully Qualified Domain Name

A complete domain name containing every required label needed to identify one node without relying on local context.

Pointer record / address-to-name lookup

A DNS lookup that starts with an IP address and uses a PTR record to return an associated name.

Email authentication and policy controls

Related email protections that authorise senders, sign messages and publish how receivers should handle authentication failures.