There are two types of fields: Dimensions (strings) and Metrics (numbers).
Usually, we use dimensions to breakdown a metric by different categories.
E.g. breakdown of Revenue by Country
or Sessions by Source / Medium.
Creating such breakdown is easy: Just add a table, add the metric and dimension, and you're done.
But what if you want to report the number of values in a dimension, to answer questions like:
How many countries did we have traffic from last month?
(i.e. number of unique values in the field Country)
How many closed deals did we have last week?
(i.e. Total number of rows where deal type equals: "Closed")
In this video, I show you a few ways to count the number of values in a field.