I understand that bitwise operations are necessary for much low-level programming, such as writing device drivers, low-level graphics, communications protocol packet assembl
Bitwise operations are extremely useful in credentials information. For example:
function is_moderator($credentials)
{ return $credentials & 4; }
function is_admin($credentials)
{ return $credentials & 8; }
and so on...
This way, we can keep a simple integer in one database column to have all credentials in the system.