Physical Reads (buffered)

Physical Reads (buffered) - Number of block read from discs into buffer cache. Values for this statistic is calculated as physical reads minus physical reads direct.

Note. Oracle 10g introduced another v$sysstat statistic : 'physical reads cache' which has same meaning. Approximately the statistics are related by this formula:
physical reads = physical reads cache + physical reads direct + physical reads direct (lob)