Glossary · Cloud & HostingActive-ActiveActive-active is a high-availability design where two or more nodes or sites serve live traffic at the same time and share the load.Glossary · Cloud & HostingActive-PassiveActive-passive is a redundancy design where one node serves traffic while an idle partner waits to take over when the active node fails.Glossary · Cloud & HostingAmazon CloudFrontAmazon CloudFront is the AWS content delivery network that caches content at edge locations worldwide to reduce latency and origin load.Glossary · Cloud & HostingAmazon EC2 (Elastic Compute Cloud)Amazon EC2 is Amazon Web Services' service for renting resizable virtual servers, called instances, billed by usage rather than bought as hardware.Glossary · Cloud & HostingAmazon RDS (Relational Database Service)Amazon RDS is the AWS managed service that runs relational databases such as MySQL and PostgreSQL and handles backups, patching and failover for you.Glossary · Cloud & HostingAmazon Route 53Amazon Route 53 is the AWS managed DNS service that hosts domain zones, answers queries globally and can route traffic using health checks.Glossary · Cloud & HostingAmazon S3 (Simple Storage Service)Amazon S3 is AWS object storage that keeps files as objects inside buckets and serves them over an HTTP API with very high durability.Glossary · Cloud & HostingAnsibleAnsible is an agentless automation tool that configures servers and deploys software over SSH using human-readable YAML playbooks.Glossary · Cloud & HostingApache HTTP ServerApache HTTP Server is a long-established open-source web server known for its modular design, .htaccess per-directory configuration and wide hosting support.Glossary · Cloud & HostingApache KafkaApache Kafka is an open-source distributed event streaming platform that stores ordered, replicated logs of records that many consumers can read independently.Glossary · Cloud & HostingAPI GatewayAn API gateway is a server that sits in front of backend services and handles routing, authentication, rate limiting and monitoring for API requests.Glossary · Cloud & HostingAuto ScalingAuto scaling automatically adds or removes servers or containers based on demand metrics such as CPU use or request count.Glossary · Cloud & HostingAWS LambdaAWS Lambda is a serverless compute service that runs your function code in response to events and bills for execution time instead of for idle servers.Glossary · Cloud & HostingBackupA backup is a separate copy of data kept so it can be restored after deletion, corruption, hardware failure or attack.Glossary · Cloud & HostingBare Metal ServerA bare metal server is a physical server rented to one customer with no hypervisor layer, giving full access to the hardware and its performance.Glossary · Cloud & HostingBFF (Backend for Frontend)A BFF is a server-side layer built for one specific client, such as a web app or mobile app, that aggregates backend calls and shapes responses for it.Glossary · Cloud & HostingBlock StorageBlock storage presents raw storage volumes to a server as disks, giving low-latency access suited to operating systems and databases.Glossary · Cloud & HostingBlue-Green DeploymentBlue-green deployment runs two identical production environments and switches traffic from the old one to the new one at once, allowing instant rollback.Glossary · Cloud & HostingBucket (Cloud Storage)A bucket is a top-level container in object storage that holds objects and has its own name, region and access policy.Glossary · Cloud & HostingCanary ReleaseA canary release rolls a new software version out to a small share of users or servers first, and expands it only if monitoring shows no problems.Glossary · Cloud & HostingCI Server (Continuous Integration)A CI server automatically builds and tests code each time changes are pushed, so problems are found before they reach production.Glossary · Cloud & HostingCloud ComputingCloud computing is the on-demand delivery of computing resources such as servers, storage and databases over the internet, billed by usage.Glossary · Cloud & HostingCloud MigrationCloud migration is the process of moving applications, data and infrastructure from on-premises systems or another provider into a cloud environment.Glossary · Cloud & HostingCloudflare WorkersCloudflare Workers is a serverless platform that runs JavaScript or WebAssembly code on Cloudflare's edge network, close to the user making the request.Glossary · Cloud & HostingCold StandbyA cold standby is a backup system that is powered off or not deployed until needed, so recovery means starting it and restoring data first.Glossary · Cloud & HostingColocationColocation is renting rack space, power and network connectivity in a data center for hardware that you own and manage.Glossary · Cloud & HostingConfiguration DriftConfiguration drift is the gradual divergence of servers or environments from their intended configuration, caused by manual changes and unrecorded fixes.Glossary · Cloud & HostingConfiguration ManagementConfiguration management is the practice of defining and enforcing the intended state of servers and software so systems stay consistent and reproducible.Glossary · Cloud & HostingContainerA container is a lightweight, isolated package that bundles an application with its dependencies and runs on a shared operating system kernel.Glossary · Cloud & HostingcPanelcPanel is a web-based hosting control panel that lets users manage websites, email, databases, domains and files without using the command line.Glossary · Cloud & HostingCron JobA cron job is a task scheduled to run automatically at set times on Unix-like systems, defined by a cron expression.Glossary · Cloud & HostingDaemonA daemon is a background process on a Unix-like system that runs without direct user interaction, typically providing a service.Glossary · Cloud & HostingDark LaunchA dark launch deploys a new feature to production and runs it for real traffic without showing it to users, to test performance and correctness safely.Glossary · Cloud & HostingData CenterA data center is a facility that houses servers, storage and networking equipment with power, cooling and security systems.Glossary · Cloud & HostingDedicated ServerA dedicated server is a physical machine leased to a single customer, who gets all of its CPU, memory, storage and network capacity.Glossary · Cloud & HostingDisaster Recovery (DR)Disaster recovery is the set of plans and tools for restoring systems and data after a major failure, such as data center loss, ransomware or deletion.Glossary · Cloud & HostingDockerDocker is a platform for building, shipping and running applications in containers, using images defined by a Dockerfile.Glossary · Cloud & HostingDrift DetectionDrift detection is the automated comparison of live infrastructure or configuration against its declared definition to find unauthorized or unrecorded changes.Glossary · Cloud & HostingEdge ComputingEdge computing runs code and processing close to users or devices, in many distributed locations, instead of in one central data center.Glossary · Cloud & HostingEgress Fees (Data Transfer Out)Egress fees are charges cloud providers bill for data leaving their network, for example to the internet or another region, usually priced per gigabyte.Glossary · Cloud & HostingFailoverFailover is the automatic or manual switch from a failed system to a standby system so that a service keeps running.Glossary · Cloud & HostingFile Descriptor LimitThe file descriptor limit caps how many open files and sockets a process can hold, and exceeding it makes new connections fail with "Too many open files".Glossary · Cloud & HostingFinOps (Cloud Financial Operations)FinOps is the practice of bringing engineering, finance and business teams together to measure, allocate and optimize cloud spending.Glossary · Cloud & HostingGoogle Cloud Platform (GCP)Google Cloud Platform is Google's public cloud offering compute, storage, networking, data analytics and machine learning services on its global infrastructure.Glossary · Cloud & HostingGraceful ShutdownA graceful shutdown lets a server stop accepting new work, finish in-flight requests and release resources before it exits.Glossary · Cloud & HostingHelm (Kubernetes Package Manager)Helm is the package manager for Kubernetes, bundling related manifests into versioned charts that can be installed, configured and upgraded as one release.Glossary · Cloud & HostingHigh Availability (HA)High availability is a system design that keeps a service running with minimal downtime by removing single points of failure and recovering automatically.Glossary · Cloud & HostingHorizontal Scaling (Scaling Out)Horizontal scaling adds more machines or instances to share the workload, rather than making a single machine more powerful.Glossary · Cloud & HostingHot StandbyA hot standby is a fully running duplicate system that mirrors the primary and can take over within seconds when the primary fails.Glossary · Cloud & HostingHybrid CloudA hybrid cloud combines private infrastructure, such as an on-premises data center, with a public cloud, connected so workloads and data can move between them.Glossary · Cloud & HostingHypervisorA hypervisor is software that creates and runs virtual machines by dividing a physical host's hardware among them.Glossary · Cloud & HostingIaaS (Infrastructure as a Service)IaaS is a cloud model that rents virtualized infrastructure such as servers, storage and networks while you manage the operating system and everything above it.Glossary · Cloud & HostingIAM (Identity and Access Management)IAM is the system in cloud platforms and organizations that defines who or what is authenticated and which actions they are allowed to perform.Glossary · Cloud & HostingImmutable InfrastructureImmutable infrastructure means servers are never modified after deployment; any change is made by building a new image and replacing the old instances.Glossary · Cloud & HostingInfrastructure as Code (IaC)Infrastructure as code manages servers, networks and cloud resources through version-controlled definition files instead of manual console clicks.Glossary · Cloud & HostingInode ExhaustionInode exhaustion means a filesystem has used all its inodes, so no new files can be created even though free disk space remains.Glossary · Cloud & HostingKubernetesKubernetes is an open-source system that automates deploying, scaling and healing containerized applications across a cluster of machines.Glossary · Cloud & HostingKubernetes ClusterA Kubernetes cluster is a set of nodes plus a control plane that together schedule, run and manage containerized applications as one system.Glossary · Cloud & HostingKubernetes IngressIngress is a Kubernetes object that defines HTTP and HTTPS routing rules from outside the cluster to internal services, handled by an ingress controller.Glossary · Cloud & HostingKubernetes NodeA Kubernetes node is a worker machine, physical or virtual, that runs pods and provides CPU, memory and networking to the cluster.Glossary · Cloud & HostingKubernetes PodA Kubernetes pod is the smallest deployable unit in Kubernetes, wrapping one or more containers that share a network address, storage and lifecycle.Glossary · Cloud & HostingLAMP StackThe LAMP stack is a classic web application platform made of Linux, Apache, MySQL (or MariaDB) and PHP (or Perl or Python).Glossary · Cloud & HostingLEMP StackThe LEMP stack replaces Apache in LAMP with Nginx, combining Linux, Nginx, MySQL or MariaDB, and PHP, usually through PHP-FPM, to host web applications.Glossary · Cloud & HostingLift and ShiftLift and shift is a cloud migration approach that moves an application to the cloud with minimal or no changes, often called rehosting.Glossary · Cloud & HostingManaged HostingManaged hosting is a hosting service where the provider handles server administration, updates, security and support in addition to the infrastructure.Glossary · Cloud & HostingMessage QueueA message queue is a service that stores messages from producers until consumers process them, decoupling systems and smoothing out traffic spikes.Glossary · Cloud & HostingMicroservicesMicroservices is an architecture that splits an application into small, independently deployable services that communicate over a network.Glossary · Cloud & HostingMicrosoft AzureMicrosoft Azure is Microsoft's public cloud platform offering virtual machines, storage, databases, networking and managed services across global regions.Glossary · Cloud & HostingMonolith (Monolithic Architecture)A monolith is an application built and deployed as a single unit, with all its features in one codebase and process.Glossary · Cloud & HostingMulti-CloudMulti-cloud is the use of two or more public cloud providers in one organization to reduce dependence, meet requirements or pick the best tool.Glossary · Cloud & HostingMulti-TenancyMulti-tenancy is an architecture where one instance of software or infrastructure serves multiple customers while keeping their data isolated.Glossary · Cloud & HostingNginxNginx is an open-source web server and reverse proxy known for handling many concurrent connections efficiently with an event-driven architecture.Glossary · Cloud & HostingObject StorageObject storage stores data as objects with metadata in flat buckets and is accessed through an HTTP API, suited to files, media and backups.Glossary · Cloud & HostingOOM KillerThe OOM killer is the Linux kernel mechanism that terminates processes when the system runs out of memory, which can silently take down a web server or database.Glossary · Cloud & HostingOrigin ServerThe origin server is the machine that holds the authoritative copy of your site content and generates responses, sitting behind any CDN, cache or proxy.Glossary · Cloud & HostingPaaS (Platform as a Service)PaaS is a cloud model where the provider runs the servers and runtime so developers deploy code without managing the underlying operating system.Glossary · Cloud & HostingPrivate CloudA private cloud is cloud-style infrastructure with self-service and elastic resources that is dedicated to one organization, on its premises or hosted for it.Glossary · Cloud & HostingProduction EnvironmentProduction is the live environment where real users access your application and where outages and bugs have real consequences.Glossary · Cloud & HostingPublic CloudA public cloud is a computing service where a provider such as AWS, Azure or Google Cloud rents shared infrastructure to many customers over the internet.Glossary · Cloud & HostingPublish/Subscribe (Pub/Sub)Publish/subscribe is a messaging pattern where publishers send messages to topics and every subscriber receives a copy without knowing the sender.Glossary · Cloud & HostingQuorumA quorum is the minimum number of nodes that must agree for a distributed system to make a decision, usually a strict majority of the voting members.Glossary · Cloud & HostingRabbitMQRabbitMQ is an open-source message broker that routes messages from producers through exchanges to queues using AMQP and other protocols.Glossary · Cloud & HostingRedundancyRedundancy means duplicating critical components, such as servers, power or network links, so that one failure does not stop the service.Glossary · Cloud & HostingRegion and Availability ZoneA region is a geographic area of a cloud provider, and an availability zone is an isolated data center location inside it designed to fail independently.Glossary · Cloud & HostingReserved InstanceA reserved instance is a cloud pricing commitment where you agree to use a certain capacity for a fixed term in exchange for a lower rate than on-demand.Glossary · Cloud & HostingRPO (Recovery Point Objective)RPO is the maximum amount of data loss a business accepts, measured as the time between the last good backup or copy and the failure.Glossary · Cloud & HostingRTO (Recovery Time Objective)RTO is the maximum acceptable time a service may stay down after a failure before it must be restored to normal operation.Glossary · Cloud & HostingSaaS (Software as a Service)SaaS is software delivered over the internet as a subscription, where the vendor hosts, maintains and updates the application for you.Glossary · Cloud & HostingServerA server is a computer or program that waits for requests over a network and returns a response, such as a web page, file or database result.Glossary · Cloud & HostingServerless ComputingServerless computing runs your code as short-lived functions on demand, with the provider handling servers and scaling and billing per execution.Glossary · Cloud & HostingService MeshA service mesh is an infrastructure layer that manages service-to-service traffic with proxies, adding encryption, retries and metrics without app changes.Glossary · Cloud & HostingSession AffinitySession affinity, or sticky sessions, makes a load balancer send all requests from one client to the same backend server.Glossary · Cloud & HostingSFTP (SSH File Transfer Protocol)SFTP is a secure file transfer protocol that runs over SSH, encrypting both login credentials and the file data being transferred.Glossary · Cloud & HostingShared HostingShared hosting places many websites on one server and splits its resources between them, usually managed through a control panel at a low price.Glossary · Cloud & HostingSidecar ContainerA sidecar is a helper container deployed beside the main application container, sharing its pod to add logging, proxying or other support features.Glossary · Cloud & HostingSnapshotA snapshot is a point-in-time copy of a disk, volume or virtual machine that can be used to roll back or create a clone.Glossary · Cloud & HostingSpot InstanceA spot instance is spare cloud compute capacity sold at a steep discount on the condition that the provider can reclaim it with short notice.Glossary · Cloud & HostingSSH (Secure Shell)SSH is an encrypted network protocol for securely logging in to and managing remote servers, typically on TCP port 22.Glossary · Cloud & HostingStaging EnvironmentA staging environment is a copy of production used to test changes under realistic conditions before releasing them to real users.Glossary · Cloud & HostingTerraformTerraform is an open infrastructure as code tool from HashiCorp that provisions cloud resources from declarative configuration files and tracks them in state.Glossary · Cloud & HostingThrottlingThrottling is the deliberate slowing or limiting of requests, connections or bandwidth by a server or provider to protect resources or enforce limits.Glossary · Cloud & HostingVendor Lock-InVendor lock-in is when switching providers is so costly or difficult that customers stay even when alternatives would suit them better.Glossary · Cloud & HostingVertical Scaling (Scaling Up)Vertical scaling increases the capacity of a single server by adding more CPU, memory or faster storage instead of adding more machines.Glossary · Cloud & HostingVirtual Machine (VM)A virtual machine is a software-emulated computer that runs its own operating system on top of a physical host through a hypervisor.Glossary · Cloud & HostingVPC (Virtual Private Cloud)A VPC is a logically isolated virtual network inside a public cloud where you define IP ranges, subnets, routing and access rules for your resources.Glossary · Cloud & HostingVPS (Virtual Private Server)A VPS is a virtual machine carved out of a physical server that gives you set CPU, memory and storage allocations and full OS control.Glossary · Cloud & HostingWarm StandbyA warm standby is a scaled-down copy of a system that is running and kept current, but needs scaling up or extra steps before it can take full production load.