# Historical data

<dl class="api-definition">
<dt>Concept</dt>
<dd><a href="/docs/development/opcua/server/historical-data">Historical data</a></dd>
</dl>

| Type | Description |
|---|---|
| [IOpcEventHistoryProvider](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.iopceventhistoryprovider/) | Defines an interface which is to be used by an [OpcNodeManager](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcnodemanager/) to provide historical event data for an [OpcObjectNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcobjectnode/). |
| [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) | Defines an interface which can be used to access and change the properties of a node and to notify about the changes performed on it. |
| [IOpcNodeHistoryProvider](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.iopcnodehistoryprovider/) | Defines an interface which is to be used by an [OpcNodeManager](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcnodemanager/) to provide and maintain historical values for an [OpcVariableNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvariablenode/). |
| [OpcAggregateType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcaggregatetype/) | Specifies an aggregate function of the OPC UA namespace, whose identifier [GetTypeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcaggregate/members#gettypeid) provides. |
| [OpcDeleteHistoryOptions](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcdeletehistoryoptions/) | Specifies the values an [IOpcNodeHistoryProvider](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.iopcnodehistoryprovider/) deletes when the history of a node is deleted within a time range. |
| [OpcEvent](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcevent/) | Represents a snapshot of a 'Opc.UaFx.OpcEventNode'. |
| [OpcEventFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventfilter/) | Represents the filter of a monitored item for events, as defined by the EventFilter of OPC UA: the select clauses define the fields to report of each event and the where clause defines the events to report. |
| [OpcHistoryModificationInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistorymodificationinfo/) | Represents the information about a modification of the history of a node: the kind and the time of the modification and the user who made it. |
| [OpcHistoryValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/) | Represents a value of the history of a node. |
| [OpcNodeHistorian](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcnodehistorian/) | Provides and maintains the history of the values of an [OpcVariableNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvariablenode/) in memory. |
| [OpcNodeHistory&lt;T&gt;](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcnodehistory-1/) | Represents a history of values kept in memory in ascending order of their timestamps, with at most one value per timestamp. |
| [OpcNodeManager](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcnodemanager/) | Provides an abstract base class used to organize and maintain the address space or only a part of it. |
| [OpcObjectNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcobjectnode/) | Defines a logical unit to represent more complex information as a [OpcVariableNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvariablenode/). |
| [OpcReadHistoryOptions](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcreadhistoryoptions/) | Specifies the values an [IOpcNodeHistoryProvider](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.iopcnodehistoryprovider/) provides when the history of a node is read. |
| [OpcServer](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserver/) | Represents an OPC UA server which provides the address space defined by its [NodeManagers](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserver/members#nodemanagers) to its clients. |
| [OpcStatusCollection](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscollection/) | Representes a collection of [OpcStatus](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatus/) instances. |
| [OpcValueCollection](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvaluecollection/) | Represents a collection of [OpcValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvalue/) instances. |