====Types====

Types provide a way of grouping similar items together. 

<WRAP info>Note that if you're familiar with the [[haystack]] structure used in building monitoring, this term can be a little confusing - please feel free to read our information on [[http://www.optrix.com.au/ardi/haystack-terms|the differences in terminology between ARDI and Haystack]].</WRAP>

In the same way that //tags// are used to categorise videos on most sharing sites and articles on news sites and blogs, //types// group together assets that have similar functions or features.

Unlike the tagging systems you might be used to though, types in ARDI form a [[hierarchy|hierarchy]] - types can have their own //sub-types//. For example, the 'Pressure Transmitter' tag will have two parents - 'Transmitter' and 'Equipment'.

This makes tagging even more effective, as you can see //all// transmitters of any kind by looking at the 'Transmitter' list, or narrow down your view by looking at only those that transmit pressure.