# Introduction to Tags ## Overview **Tags** are fundamental to how Taglo software works. As their name suggests, they can be used for "tagging", helping to categorise and search items, but with some extra layers of power built in: Tags can be linked to other Tags, creating a network that makes both tagging and searching easier and more effective. The relationships between Tags makes them useful in other places too, and they form the basis for other concepts in [**Models**](https://help.taglo.io/models), such as [**Units**](https://help.taglo.io/units) and [**Dimensions**](https://help.taglo.io/dimensions). ## Abstract vs. Concrete Tags can be one of two types: `Abstract` and `Concrete`
Tag typeDescriptionExample
AbstractDescribes a type of object or concept that there can be one or more instances of (e.g., a city, a country, an apple variety, a Taglo product, an emotional state)
ConcreteDescribes a specific instance of an object, or a general concept of which there can be only one instance (e.g., London, United Kingdom, Granny Smith , Models, happiness)
## Tag Relationships Tags can have unlimited parents (and children). There are two types of parent relationships: 1. `Is A`: Links to `Abstract` parents (e.g., `Is A` ) 2. `Relates To`: Links to `Concrete` parents (e.g., `Relates To` ) {% hint style="info" %} Use the [Tags Applet](https://help.taglo.io/tags/tags-applet) to quickly navigate between Tags and explore relationships {% endhint %} {% hint style="warning" %} There is also an `Is Same As` relationship, which should only be used when duplicate Tags have been created and it would be difficult to remove one of the duplicates. In this case each Tag in the `Is Same As` relationship will inherit all parents of the other. {% endhint %}