Dimension
What is a dimension?
A dimension is a descriptive, qualitative attribute of your data, like a name, category, or URL field. Often you will filter or group a measure measure or metric by a dimension, like grouping revenue (the metric) by state (the dimension).
Unlike measures, dimensions can’t be calculated or computed; they’re discrete and categorical. That is, you can’t determine the average name or standard deviation of a field containing user birthdays.
Example dimension
A product’s category is a dimension of that product, and the average price of that product (the measure) could be grouped or filtered by that dimension.