IT & Telecom Glossary

Technical terms in information technology and telecommunications, from A to Z. Use the search field to find definitions quickly.

API: Application Programming Interface — a set of definitions and protocols that enables communication between software systems.
ARP: Address Resolution Protocol — a protocol that maps IP addresses to MAC addresses on the local network.
BGP: Border Gateway Protocol — a routing protocol between autonomous systems (ASes) on the internet.
CIDR: Classless Inter-Domain Routing — notation for specifying IP addresses and their subnet masks (e.g., /24).
Cloud Computing: A model for delivering IT resources (servers, storage, networking) on-demand over the internet.
DHCP: Dynamic Host Configuration Protocol — a protocol that automatically assigns IP addresses to devices on a network.
DNS: Domain Name System — a system that translates domain names (e.g., voitt.com) into IP addresses.
Firewall: A security system that monitors and controls network traffic based on predefined rules.
FTP: File Transfer Protocol — a protocol for transferring files between a client and server.
Gateway: A device or software that acts as an entry/exit point between two different networks.
HTTP: HyperText Transfer Protocol — the foundational protocol for communication on the World Wide Web.
HTTPS: HTTP Secure — the encrypted version of HTTP using TLS/SSL for secure communication.
IaaS: Infrastructure as a Service — a cloud model where infrastructure (VMs, networking, storage) is provided on-demand.
ICMP: Internet Control Message Protocol — a protocol used for network diagnostics (ping, traceroute).
IoT: Internet of Things — a network of physical devices connected to the internet, collecting and exchanging data.
IP: Internet Protocol — the fundamental protocol for addressing and routing packets on the internet.
IPv6: Internet Protocol version 6 — the successor to IPv4, with 128-bit addresses (e.g., 2001:db8::1).
LAN: Local Area Network — a computer network within a limited geographic area (office, building).
Latency: The time it takes for a data packet to travel from one point to another on the network. Measured in milliseconds (ms).
Load Balancer: A device or service that distributes network traffic across multiple servers to optimize performance.
MAC Address: Media Access Control — a unique 48-bit physical address assigned to each network interface.
MPLS: Multiprotocol Label Switching — a label-based packet forwarding technique used in WANs.
NAT: Network Address Translation — a technique that translates private IP addresses to public ones for internet access.
NTP: Network Time Protocol — a protocol for synchronizing clocks across networked systems.
OSPF: Open Shortest Path First — a link-state dynamic routing protocol.
PaaS: Platform as a Service — a cloud model that provides a platform for developing and deploying applications.
Ping: A utility that sends ICMP Echo Request packets to verify connectivity with a remote host.
QoS: Quality of Service — a set of techniques for managing and prioritizing network traffic.
RDP: Remote Desktop Protocol — a Microsoft protocol for remote access to Windows desktops.
SaaS: Software as a Service — a cloud model where software is delivered as a service over the internet (e.g., Gmail, Salesforce).
SDN: Software-Defined Networking — a network architecture where the control plane is separated from the data plane and is programmable.
SIP: Session Initiation Protocol — a signaling protocol used in VoIP to initiate, maintain, and terminate sessions.
SMTP: Simple Mail Transfer Protocol — the standard protocol for sending email.
SNMP: Simple Network Management Protocol — a protocol for monitoring and managing network devices.
SSH: Secure Shell — an encrypted network protocol for secure remote server access.
SSL/TLS: Secure Sockets Layer / Transport Layer Security — cryptographic protocols for secure internet communication.
Subnet: A logical division of an IP network into smaller segments for organization and security.
TCP: Transmission Control Protocol — a reliable, connection-oriented transport protocol with guaranteed delivery.
UDP: User Datagram Protocol — a fast, connectionless transport protocol without delivery guarantees. Used in VoIP, streaming.
VLAN: Virtual Local Area Network — a logical segmentation of a physical network into multiple isolated virtual networks.
VLSM: Variable Length Subnet Masking — a technique that allows creating subnets of different sizes within a network.
VoIP: Voice over Internet Protocol — technology that enables voice calls over the internet instead of traditional phone lines.
VPN: Virtual Private Network — a private virtual network that creates an encrypted tunnel over a public network.
WAN: Wide Area Network — a network spanning a large geographic area, connecting multiple LANs. The internet is the largest WAN.