The scoping operator used in many object oriented, or OO programming languages to specify what class, object (and/or namespace in c++) a function or variable belongs to. If you see the following code:

	std::cout

This would tell you that the output stream instance cout belonged to the namespace std.


And for those of you giggling over "std" in the peanut gallery, maybe you can share what's so funny with us coders? :)

18.09.01: Thanks to Wicker808 for the factual corrections!