what is table gather stats in oracle code example

Example: oracle gather table statistics

CALL DBMS_STATS.GATHER_TABLE_STATS(
    'OWNER_NAME',
    'TABLE_NAME',
    ESTIMATE_PERCENT => 50,			-- longer but better than 1 for exec plans
    GRANULARITY => 'PARTITION',   	-- or SUBPARTITION or nothing  
    PARTNAME => 'PARTITION_NAME', 	-- or nothing
    DEGREE => 8                 	-- parallelism
);