[jQuery] $().someFunction(); -- The First Pair of Parentheses?

[kiusau]

QUESTION:  What does the first pair of parentheses indicate in the
following statement:

        $().getBrowserInformation();

BACKGROUND:  I have noticed that their presence or absence can make or
break JavaScript's acknowledgement of a method's existence on the one
hand, but seem entirely unnecessary under other circumstances.

Roddy