Ask HN: Simplest word to describe key/value store?

I am currently developing an app that uses customised key-value stores, but am struggling to come up with a simple way to describe this concept.

In the app, users can add custom meta data to objects. For example, a 'restaurant' object can contain metadata with <Rating, Int>, <Website, URL>, <Menu, Photo> and so on. Other another example would be a 'walking goal' object with custom meta data of <Time Taken, Date> and <Steps, Int>

I'm thinking of words like 'properties' or 'attributes', but I think the word/concept can be simplified further.

Thanks in advance!