# Read and write values

<dl class="api-definition">
<dt>Concept</dt>
<dd><a href="/docs/development/opcua/client/read-write-values">Read and write values</a></dd>
</dl>

| Type | Description |
|---|---|
| [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | Identifies the different attributes which define the characteristics and additional metadata of a node. |
| [OpcClient](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/) | Provides session based methods to access OPC UA server services. |
| [OpcNamespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnamespace/) | Represents a nominal space used to categorize information like nodes, types, identifiers, etc. under a logical topic. |
| [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | Defines an identifier for a node in the address space of an OPC UA Server. |
| [OpcNodeIdCollection](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeidcollection/) | Represents a collection of [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) instances. |
| [OpcNodeValue&lt;T&gt;](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodevalue-1/) | Stores the generic value of the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute associated with a specific node optionally associated with status and timestamp information. |
| [OpcRange](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcrange/) | Represents a range used to identify a single element or a range of elements in a structure or an array using their zero-based indexes. |
| [OpcReadNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadnode/) | Defines a single command of the [IOpcReadNodesService](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.iopcreadnodesservice/). |
| [OpcStatus](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatus/) | Provides information about the outcome of an operation. |
| [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. |
| [OpcTimestampSource](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctimestampsource/) | Defines the source of the timestamp to use for [OpcValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvalue/) instances. |
| [OpcValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvalue/) | Stores a value optionally associated with status and timestamp information. |
| [OpcWriteNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwritenode/) | Defines a single command of the [IOpcWriteNodesService](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.iopcwritenodesservice/). |