[comment]: # ({bd3d4e41-bd3d4e41}) # 2 Definitions [comment]: # ({/bd3d4e41-bd3d4e41}) [comment]: # ({99b1c1f4-99b1c1f4}) #### Overview In this section you can learn the meaning of some terms commonly used in Zabbix. [comment]: # ({/99b1c1f4-99b1c1f4}) [comment]: # ({761d15cb-77400725}) #### Definitions ***[host](/manual/config/hosts)*** \- *any physical or virtual device, application, service, or any other logically-related collection of monitored parameters.* ***[host group](/manual/config/hosts)*** \- *a logical grouping of hosts. Host groups are used when assigning access rights to hosts for different user groups.* ***[item](/manual/config/items)*** \- *a particular piece of data that you want to receive from a host, a metric of data.* ***[value preprocessing](/manual/config/items/item#item_value_preprocessing)*** \- *a transformation of received metric value* before saving it to the database. ***[trigger](/manual/config/triggers)*** \- *a logical expression that defines a problem threshold and is used to "evaluate" data received in items.* When received data are above the threshold, triggers go from 'Ok' into a 'Problem' state. When received data are below the threshold, triggers stay in/return to an 'Ok' state. ***[template](/manual/config/templates)*** \- *a set of entities (items, triggers, graphs, low-level discovery rules, web scenarios) ready to be applied to one or several hosts.* The job of templates is to speed up the deployment of monitoring tasks on a host; also to make it easier to apply mass changes to monitoring tasks. Templates are linked directly to individual hosts. ***[template group](/manual/config/templates)*** \- *a logical grouping of templates. Template groups are used when assigning access rights to templates for different user groups.* ***[event](/manual/config/events)*** \- *a single occurrence of something that deserves attention such as a trigger changing state or a discovery/agent autoregistration taking place.* ***[event tag](/manual/config/tagging)*** \- *a pre-defined marker for the event.* It may be used in event correlation, permission granulation, etc. ***[event correlation](/manual/config/event_correlation)*** \- *a method of correlating problems to their resolution flexibly and precisely.* For example, you may define that a problem reported by one trigger may be resolved by another trigger, which may even use a different data collection method. ***[problem](/manual/web_interface/frontend_sections/monitoring/problems)*** \- *a trigger that is in "Problem" state.* ***[problem update](/manual/acknowledgment#updating_problems)*** \- *problem management options provided by Zabbix, such as adding comment, acknowledging, changing severity or closing manually.* ***[action](/manual/config/notifications/action)*** \- *a predefined means of reacting to an event.* An action consists of operations (e.g. sending a notification) and conditions (*when* the operation is carried out) ***[escalation](/manual/config/notifications/action/escalations)*** \- *a custom scenario for executing operations within an action; a sequence of sending notifications/executing remote commands.* ***[media](/manual/config/notifications/media)*** \- *a means of delivering notifications; delivery channel.* ***[notification](/manual/config/notifications/action/operation/message)*** \- *a message about some event sent to a user via the chosen media channel.* ***[remote command](/manual/config/notifications/action/operation/remote_command)*** \- *a pre-defined command that is automatically executed on a monitored host upon some condition.* ***[web scenario](/manual/web_monitoring)*** \- *one or several HTTP requests to check the availability of a web site.* ***[frontend](/manual/introduction/overview#architecture)*** \- *the web interface provided with Zabbix.* ***[dashboard](/manual/web_interface/frontend_sections/dashboards)*** \- *customizable section of the web interface displaying summaries and visualizations* of important information in visual units called widgets. ***[widget](/manual/web_interface/frontend_sections/dashboards/widgets)*** \- *visual unit displaying information of a certain kind and source* (a summary, a map, a graph, the clock, etc.), used in the dashboard. ***[Zabbix API](/manual/api)*** \- *Zabbix API allows you to use the JSON RPC protocol to create, update and fetch Zabbix objects (like hosts, items, graphs and others) or perform any other custom tasks.* ***[Zabbix server](/manual/concepts/server)*** \- *a central process of Zabbix software that performs monitoring, interacts with Zabbix proxies and agents, calculates triggers, sends notifications; a central repository of data.* ***[Zabbix proxy](/manual/concepts/proxy)*** \- *a process that may collect data on behalf of Zabbix server, taking some processing load from the server.* ***[Zabbix agent](/manual/concepts/agent)*** \- *a process deployed on monitoring targets to actively monitor local resources and applications.* ***[Zabbix agent 2](/manual/concepts/agent2)*** \- *a new generation of Zabbix agent to actively monitor local resources and applications, allowing to use custom plugins for monitoring.* ::: noteimportant Because Zabbix agent 2 shares much functionality with Zabbix agent, the term "Zabbix agent" in documentation stands for both - Zabbix agent and Zabbix agent 2, if the functional behavior is the same. Zabbix agent 2 is only specifically named where its functionality differs. ::: ***[encryption](/manual/encryption)*** \- *support of encrypted communications between Zabbix components (server, proxy, agent, zabbix\_sender and zabbix\_get utilities)* using Transport Layer Security (TLS) protocol. ***[agent autoregistration](/manual/discovery/auto_registration)*** \- *automated process whereby a Zabbix agent itself is registered* as a host and started to monitor. ***[network discovery](/manual/discovery/network_discovery)*** \- *automated discovery of network devices*. ***[low-level discovery](/manual/discovery/low_level_discovery)*** \- *automated discovery of low-level entities on a particular device* (e.g. file systems, network interfaces, etc). ***[low-level discovery rule](/manual/discovery/low_level_discovery#discovery_rule)*** \- *set of definitions for automated discovery of low-level entities* on a device. ***[item prototype](/manual/discovery/low_level_discovery#item_prototypes)*** \- *a metric with certain parameters as variables, ready for low-level discovery*. After low-level discovery the variables are automatically substituted with the real discovered parameters and the metric automatically starts gathering data. ***[trigger prototype](/manual/discovery/low_level_discovery#trigger_prototypes)*** \- *a trigger with certain parameters as variables, ready for low-level discovery*. After low-level discovery the variables are automatically substituted with the real discovered parameters and the trigger automatically starts evaluating data. *Prototypes* of some other Zabbix entities are also in use in low-level discovery - graph prototypes, host prototypes, host group prototypes. [comment]: # ({/761d15cb-77400725})