Tags and annotations are easily confused. An annotation can and often does display a tag, but it can also display other information.
Here you see the tag as data in the Properties palette on the left and in an annotation in a drawing on the right: 
| A tag is: | An annotation is: |
|---|---|
| A unique identifier for a component or line segment | Information about a component or line segment that appears on a drawing |
| Data | Text and (optional) shapes |
| Located in the data cache | Located in the drawing area |
| Unique | Not necessarily unique |
| Viewable as a property in the Data Manager | Viewable in the drawing |
| A single entity for each component or line segment | A component or line segment can have multiple annotations. |
| Not text, but data. Comprised of sub parts as defined by the tag format. | Text defined in the annotation style block definition. This text can include the tag property of a component or line segment. This text is not a tag, but an annotation. |