There are several different aggregate flow types including:
AS matrix
Destination prefix matrix
Source prefix matrix
Prefix matrix
Protocol/port matrix.
Version 8 is an aggregated export format. As individual flows are aged out of the raw flow cache, the data is added to the aggregate flow cache for each configured aggregate type. Each of these aggregate flows are also aged in a manner similar to the method the active flow cache entries are aged. When an aggregate flow is aged out, it is sent to the external collector in the V8 record format.