Another asumption: The object that is in $q is an object created by one of the many CGI modules that exist. A well known one that I have used is CGI.pm by Lincoln Stein.
The syntax that is used as well as the name of the method
"param" suggest it is CGI.pm.
This method returns several items of in about the parameters submitted from a form including its values. Depending on how
the object is created all of the parameters that are submitted will have values.