In ActivityInfo, a Report is a presentation of data stored in the Databases you have access to. This presentation can take the form of a visualization or tabulation, depending on your reporting requirements.
A visualization in ActivityInfo is a graphic presentation of data. These can be Charts (for instance, a Bar Chart).
A tabulation in ActivityInfo is a tabular presentation of data, similar to an Excel table. ActivityInfo gives you a flexible way to construct a table with many data points via Pivot Tables.
You are free to choose from all of the data you have access to when constructing a Report in ActivityInfo. These data can then be filtered, grouped and sorted to meet your reporting needs.