Please don't SHOUT. The question is too vague for an answer. In common English parlance, "Oops" is a mild exclamation uttered after a small accident:
open my $fh, "<", $filename or die "Oops: can't open $filename for reading: $!\n";
Alternatively, "OOP" is an abbreviation for "Object Oriented Programming", and "OOPS" might be an abbreviation for object oriented programming style, or objected oriented Perl style, or maybe even object oriented paradigm shift. We don't know the context, so can't really help much more than this. If this is something to do with object oriented perl, look at the OO docs like perltoot, as virtualsue suggested.