$Variables can be used when writing programs to populate learner names and pronouns so when you share a template or program to another learner, the names/pronouns will auto populate.
Learner nicknames will populate when you use any of the following $learner, $child, $student, $patient, $subject
Pronouns can be $he translates to she/he, $she translates to she/he, $her translates to her/his, $hers translates to her/his, $him translates to her/him
$Variables can also be used as a way to build parameters so that target or goal names are auto-populated into a program so that you don't need to customize the interface for each target.
Target can be $target or $goal