> For the complete documentation index, see [llms.txt](https://docs.monokot.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.monokot.io/tags-and-devices/tags.md).

# Tags

**Tag** represents the area of device data identified by the specific address. Address identifies the data type and the dimension (scalar or array). Tags are organized in a hierarchy, which forms the objects structure of the OPC UA items, where the folder is a group of tags, and a variable is a tag.