> For the complete documentation index, see [llms.txt](https://docs.onum.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.onum.com/key-terminology.md). # Key Terminology ### **Action** A unit of work performing a given operation on an event. *** ### **API** Application Programming Interface. A set of defined methods of communication among various components. *** ### **Cluster** Various distributors and workers can be grouped and contained within a cluster. You can have as many clusters as required per Tenant. *** ### **Data Sink** Where the data is routed after being processed by Onum. *** ### **Data source** Where the data is generated before ingesting it into Onum, e.g. application server logs, firewall logs, S3 bucket, Kafka Topic, etc. *** ### **Distributor** This service receives and processes the Listener data before sending it on to workers within a cluster. *** ### **Event** An event represents semi-structured data such as a log entry. Events can be parsed so that structured data can be generated and eventually processed by the engine. Events are composed of fields, which are referred to as **Field**. An action that produces a new field will be referred to as **outputField.** *** ### **Label** Used to sort events coming from Listeners into categories or sets that meet given filters to be used in a Pipeline. *** ### **Listener** A Listener retrieves events in a given IP address and a port, routing the data to the Pipelines so that it can be processed. *** ### **Lookup** A **lookup** refers to searching for and retrieving information from a specific source or dataset, typically based on a key or reference. *** ### **Multitenancy** Multitenancy is an architecture in which tenants share the same underlying infrastructure, including databases and application code, but their data and configurations are kept separate to ensure privacy and security. *** ### **Pipeline** A sequence of Actions connected through inputs/outputs to process a stream of data. Data comes from the Listener and eventually is routed to a Datasink. *** ### **Role** A role is assigned to a user in order to control the access they have to certain or all Onum features. This way, we can personalise the experience for each user. *** ### **Tag** Tags can be assigned to Listeners, Pipelines or Data sinks in order to classify them or make them easier to find. This is particularly useful if you have a wide database and want to avoid lengthy searching for the resources you wish to use. *** ### **Tenant** A Tenant is a domain that contains a set of data in your organization. You can use one or various tenants and grant access to as many as required. *** ### **Worker** This service runs the Pipelines, receiving data from its distributor and contained within a Cluster.\