Terms from hosting, networks, databases, and DevOps — in plain language with real examples.
A DNS record that maps a domain name to the corresponding IPv4 address of a host.
A DNS resource record that maps a domain name to a 128-bit IPv6 address.
A free, open-source Linux distribution providing 1:1 binary compatibility with Red Hat Enterprise Linux (RHEL).
An open-source IT automation engine used for configuration management, application deployment, and task orchestration through an agentless architecture.
A network routing methodology where a single IP address is shared by multiple servers across different geographical locations.
A network routing methodology where multiple DNS servers share the same IP address and respond to queries based on topological proximity.
An open-source, modular web server software designed to process HTTP requests and serve web content across various operating systems.
A copy of data stored on a separate medium used to restore information in case of loss, damage, or system failure.
A single-tenant physical server where the operating system is installed directly on the hardware without a hypervisor or virtualization layer.
A standardized exterior gateway protocol designed to exchange routing and reachability information among autonomous systems (AS) on the Internet.
A type of networked storage that provides data access as a set of fixed-size logical blocks without a file system layer.
Btrfs is a Linux file system based on B-trees that uses copy-on-write (CoW) to provide advanced features like snapshots and built-in RAID.
A geographically distributed network of proxy servers and data centers that speeds up content delivery by caching data closer to end users.
A rolling-preview Linux distribution that serves as the upstream development platform for upcoming Red Hat Enterprise Linux (RHEL) minor releases.
A Linux kernel feature that limits, accounts for, and isolates resource usage (CPU, memory, I/O) for groups of processes.
CI/CD is a software development methodology that automates the build, test, and deployment stages to deliver code changes more frequently and reliably.
A hosting method where applications and websites are hosted on a network of interconnected virtual servers that distribute load across physical nodes.
A multi-distribution package that handles early initialization of cloud instances during their first boot.
A type of DNS resource record that maps an alias name to a true or canonical domain name.
A service where a business rents space for its own servers and hardware in a professional data center facility.
An immutable file containing executable code, libraries, and dependencies required to run an application in an isolated environment.
A specialized service for storing, managing, and distributing container images and their versions.
Software responsible for executing containers, managing their lifecycle, and enforcing resource isolation on a host system.
The primary component of a computer that executes instructions and manages data flow between other hardware elements.
A physical processing unit within a CPU that independently executes a stream of instructions.
cron is a time-based job scheduler in Unix-like operating systems that runs background processes at specified intervals.
A scheduled task executed automatically at specific intervals or times by the cron daemon in Unix-like operating systems.
A distributed attack aimed at overwhelming network resources or applications with traffic from multiple sources to cause service unavailability.
An independent GNU/Linux distribution utilizing the APT package manager and .deb format as its standard.
A physical server where all hardware resources, including CPU, RAM, and storage, are exclusively allocated to a single client.
An email authentication method that uses a digital signature to verify the sender's domain and ensure the message content has not been altered.
A technical protocol that defines how to handle emails that fail SPF and DKIM authentication checks using a domain-level policy.
DNS is a hierarchical distributed naming system used to resolve domain names into machine-readable IP addresses.
A platform for automating the deployment and management of applications within isolated environments called containers.
A tool for defining and running multi-container Docker applications using YAML configuration files.
A unique alphanumeric identifier used to locate and address network resources within the Domain Name System (DNS).
An accredited organization authorized to reserve domain names in top-level registries and manage their records.
A type of computer data storage that can detect and correct the most common kinds of internal data corruption.
A distributed computing paradigm that brings computation and data storage closer to the sources of data to improve response times and save bandwidth.
The fourth extended filesystem (ext4) is a journaling file system for Linux, serving as the default for most distributions.
An intrusion prevention framework that monitors log files and bans IP addresses exhibiting malicious behavior, such as repeated failed login attempts.
A security system that monitors and filters incoming and outgoing network traffic based on an organization's previously established security policies.
HAProxy is a high-performance, open-source software solution for TCP/HTTP load balancing and proxying.
A hard link is a directory entry that associates a name with a specific inode on a filesystem, allowing multiple names to point to the same physical data.
An electromechanical data storage device that uses magnetic storage to store and retrieve digital information using rotating platters.
A content management system that provides content through an API without a built-in frontend layer.
A company that provides the infrastructure and computing resources required to host websites, applications, and data on the internet.
A security policy mechanism that forces browsers to communicate with a server exclusively over encrypted HTTPS connections, blocking insecure HTTP access.
A mechanism for storing local copies of HTTP responses to fulfill subsequent requests without re-contacting the origin server.
An extension of the Hypertext Transfer Protocol (HTTP) that uses TLS or SSL to encrypt communication for secure data transfer.
Intel's proprietary implementation of Simultaneous Multithreading (SMT) that allows a single physical CPU core to execute two threads concurrently.
Software or firmware that creates and manages virtual machines by isolating and distributing physical hardware resources.
An application layer protocol used by email clients to retrieve and manage messages on a mail server while keeping them synchronized across devices.
A backup method that captures only the data that has changed since the last backup operation of any type.
An inode is a filesystem data structure that stores metadata about a file, including its size, permissions, and data block pointers, but excluding the filename.
The number of read and write operations a storage device performs per second.
A unique numerical identifier assigned to each device connected to a computer network that uses the Internet Protocol for communication.
A command-line utility for configuring IP packet filter rules and network address translation in the Linux kernel.
The fourth version of the Internet Protocol, utilizing 32-bit addresses to identify devices on a network.
A network layer protocol that uses 128-bit addressing to replace IPv4 and resolve the exhaustion of available IP addresses.
The time delay between a request for data and the start of the data's transfer.
A non-profit certificate authority that provides free SSL/TLS certificates to enable automated website encryption.
A family of open-source Unix-like operating systems based on the Linux kernel.
A Linux kernel feature that partitions kernel resources so that processes see isolated instances of global resources.
A device or software that distributes incoming network traffic across a group of backend servers to optimize resource utilization and ensure high availability.
A Linux kernel subsystem that provides a layer of abstraction between physical storage and file systems for flexible volume management.
LXC (Linux Containers) is an OS-level virtualization method for running multiple isolated Linux systems on a single host using a shared kernel.
An open-source relational database management system developed as a community-driven, binary drop-in replacement for MySQL.
A document-oriented NoSQL database that stores data in flexible, JSON-like BSON documents.
A directory in a file system hierarchy used as an access point for a storage device, partition, or network resource.
An MX record is a DNS resource record that specifies the mail servers responsible for receiving email messages for a domain.
An open-source relational database management system that uses SQL for managing and querying structured data.
A networking method that maps multiple private IP addresses to a single public IP address by modifying packet header information.
A Linux kernel subsystem for network packet filtering and classification, designed as a modern replacement for the legacy iptables framework.
A high-performance HTTP server and reverse proxy utilizing an asynchronous event-driven architecture.
A high-performance storage protocol designed to access non-volatile memory media attached via a PCI Express bus.
A network utility that tests host reachability and measures round-trip time using the ICMP protocol.
A Point of Presence (PoP) is a physical location that houses servers and networking equipment to provide local access to a network or content delivery services.
An application-layer protocol used by email clients to retrieve messages from a remote server over a TCP/IP connection.
A 16-bit numerical identifier in TCP and UDP protocol headers used to direct data to a specific process or service on a networked host.
An open-source object-relational database management system emphasizing SQL compliance and extensibility.
System software designed to automatically start, monitor, and restart background processes and services.
A data storage virtualization technology that combines multiple physical disk drive components into one or more logical units for data redundancy or performance improvement.
RAID 0 is a non-redundant disk array that uses striping to increase performance by spreading data across multiple drives.
A data storage virtualization technology that replicates data onto two or more drives to provide redundancy and fault tolerance.
A nested RAID level combining disk mirroring and striping to provide high performance and fault tolerance.
A fault-tolerant disk array using block-level striping and distributed parity to protect data against a single drive failure.
Redis is an open-source, in-memory data structure store used as a distributed, key-value database, cache, and message broker.
A business model where a provider sells server resources to a third party, who then resells them to end clients as their own hosting service.
REST API is an architectural style for distributed systems that uses the HTTP protocol to manage and interact with resources.
An intermediary server that receives incoming client requests and forwards them to one or more internal backend servers.
A method for accessing a machine behind a NAT or firewall by establishing an outbound connection to a remote server that forwards incoming traffic back to the client.
A cloud computing model where the cloud provider automatically manages the infrastructure, abstracting server management from the developer.
A type of web hosting where multiple websites reside on a single physical server and share its common system resources.
A formal contract between a service provider and a customer that specifies measurable performance and reliability metrics.
An application layer protocol used for sending and relaying email messages between clients and servers or between mail servers.
A snapshot is a point-in-time image of a file system, database, or virtual machine state.
An email authentication method that specifies the mail servers authorized to send email on behalf of a domain via a DNS record.
A non-volatile storage device that uses integrated circuit assemblies to store data persistently without moving parts.
An application layer protocol for secure remote operating system management and encrypted data communication.
An authentication credential for the SSH protocol that uses a pair of cryptographic keys for secure server access.
Cryptographic protocols designed to provide secure communication and data integrity between a client and a server over a network.
A logical subdivision of an IP network designed to improve routing efficiency, manage traffic, and enhance security.
A virtual memory mechanism that moves inactive segments of RAM to secondary storage to free up physical memory for active processes.
A special file type that stores a text path to another file or directory, acting as a transparent pointer for the operating system.
An init system and service manager for Linux-based operating systems.
A connection-oriented transport layer protocol that provides reliable, ordered, and error-checked delivery of a stream of octets between applications.
An open-source tool for managing cloud and on-premises infrastructure through declarative configuration files.
TTL (Time To Live) is a numerical value in seconds that determines how long a DNS record is cached by resolvers before a fresh query to the authoritative server is made.
A type of DNS resource record that allows a domain owner to store arbitrary text information for use by external services.
A Linux distribution based on Debian and developed by Canonical Ltd.
A connectionless transport layer protocol that transmits data without handshakes or delivery guarantees, minimizing latency.
A command-line interface for managing Netfilter firewall rules, designed to simplify network security configuration in Linux environments.
The period during which a computer system or service is operational and available for use.
A virtual processor representing a time slice of a physical CPU core or thread, allocated by a hypervisor to a virtual machine.
A technology that creates an encrypted tunnel over a public network to ensure secure data transmission.
A virtual machine that provides dedicated system resources on a shared physical server through virtualization technology.
A mechanism for real-time notification of events to external systems via HTTP POST requests.
A query and response protocol used for querying databases that store the registered users or assignees of an Internet resource.
A Wildcard SSL is a digital certificate that secures a primary domain and an unlimited number of its first-level subdomains.
WireGuard is a modern, open-source communication protocol designed for creating fast and secure virtual private networks (VPNs).
An open-source content management system (CMS) based on PHP and paired with a MySQL or MariaDB database.