Granularity refers to the level of detail or summarization in
the units of in the data warehouse (Inmon, WH 2002). For example,
one of the dimension might be a date/time dimension which could be
at the year, month, quarter, period, week, day, hour, minute,
second, hundredths of seconds level of granularity. High
granularity means that the data is at or near the transaction
level, which has more detail. Low granularity means that the data
is aggregated, which has less detail.