Joomla! Documentation™

<name>	the name of the variable to be retrieved (for example, the name of an argument in a URL).
<default>	the default value. There is no default value that will be returned if no default is specified in the call the JInput->get. If no default is specified and the argument is not present in the request variable then it will return undefined.
<type>	specifies the data type expected (see below).