Ansible
A tool automating system configuration and deployments through declared tasks. Playbooks make operations repeatable, while their correctness and safety still need review.
Definition and sourcesKNOWLEDGE / FROM A TO Z
Glossary
Technology, explained clearly. Find a term, choose a letter or narrow the topic. Definitions include sources and their review date.
Terms 95 / 685
Clear filtersApache HTTP Server
A web server handling HTTP and HTTPS requests. Modules support redirects and application integration; configuration affects security and performance.
Definition and sourcesAPI (Application Programming Interface)
An interface defining how software can use another component's functions or data. It specifies available operations and communication rules. An API can belong to a local library; it need not operate over the internet.
Definition and sourcesApplication performance monitoring
Monitoring application behaviour through latency, error and dependency measurements. APM supports diagnosis, but collecting metrics alone does not fix incidents.
Definition and sourcesBackup
A data copy intended for recovery after loss or corruption. Usefulness depends on freshness, separation and tested restoration, not merely a completion message.
Definition and sourcesCache
Storage of data for reuse, such as a saved HTTP response. Caching reduces delays and repeated work. Expiration and invalidation matter; private responses must not be indiscriminately stored in a shared cache.
Definition and sourcesCache and microcache
Caches store responses or computation results for reuse. Microcaching uses short lifetimes; private and session-specific content needs exclusion from shared caches.
Definition and sourcesCDN (Content Delivery Network)
Distributed infrastructure delivering content from multiple locations. A CDN can cache assets and reduce origin-server load. Node selection depends on routing and configuration, not necessarily physical proximity.
Definition and sourcesChaos engineering
Controlled disruption experiments used to test system resilience. They require hypotheses, observation and bounded impact; randomly stopping services is insufficient.
Definition and sourcesCloud computing
A model for on-demand access to shared computing resources. Cloud changes infrastructure delivery but does not automatically transfer all application responsibility.
Definition and sourcesCloudflare
A network-services provider offering CDN, DNS, application protection and the Workers computing platform. Services operate differently. Enabling Cloudflare does not replace application updates or correct access configuration.
Definition and sourcesCluster
Cooperating nodes performing a shared task. A cluster can support scaling or availability but does not guarantee resilience to every failure.
Definition and sourcesCookies
Small pieces of data stored by a browser for a website, used for sessions, preferences, analytics or advertising. Cookies are not programs. Consent requirements depend on purpose and applicable rules.
Definition and sourcesCron
A system service executing commands according to a crontab schedule, for example backups. Time zones, permissions and overlapping runs need attention. Cron schedules execution; it does not guarantee the task succeeds.
Definition and sourcesCron job
A task executed on a schedule by cron. It needs a correct environment, permissions and error handling; scheduling does not guarantee success.
Definition and sourcesCrontab
A table or file of cron scheduling rules. It contains execution times and commands; field interpretation and timezone support depend on the implementation.
Definition and sourcesDDoS (Distributed Denial of Service)
An attack using traffic from multiple sources to exhaust resources and disrupt legitimate access. Defence may require upstream filtering and distributed infrastructure. An application firewall alone cannot handle every kind of DDoS.
Definition and sourcesDebian
A community-developed operating-system distribution. It provides packages and updates; release-branch choice affects stability, available versions and support.
Definition and sourcesDirectAdmin
A hosting administration panel for domains, email and accounts. Available functionality depends on permissions and server configuration.
Definition and sourcesDisaster recovery plan
A plan for restoring services after major disruption. It defines roles, dependencies, recovery order and timing goals; it must be exercised, not just documented.
Definition and sourcesDNS (Domain Name System)
A hierarchical, distributed naming system. DNS records can identify IP addresses, mail servers and other information. A domain need not correspond to one website or server; DNS answers are also cached.
Definition and sourcesDocker
A platform for building and running application containers. Containers usually share the host kernel; they are not automatically full virtual machines or absolute isolation boundaries.
Definition and sourcesFail2ban
A tool analysing logs and temporarily blocking sources of defined abuse. It requires suitable rules and does not replace updates, strong authentication or large-scale DDoS protection.
Definition and sourcesFirewall
A mechanism controlling network traffic according to rules. It can operate at different layers; permitting a connection does not prove application safety.
Definition and sources