Metrics reports show multiple columns of metrics for rows with a single dimension
*Example: "Metrics" report, showing "Medium" as the dimension, with multiple metrics
Trended reports show the progression of metrics over time (based on event time).
Granularity can be set to show per day, per week or per month.
*Example: "Trended" report showing a number of metrics by week, within the specified date range
Cross-Tab reports show a one metric over the intersection two dimensions in rows and columns
*Example: Cross-Tab report showing contacts passed to sales, per business unit, per medium, within the specified date range.