Simplify the following text for a Grade 7 native English-speaking person.
Original: The performing arts are those forms of art which differ from the plastic arts insofar as the former uses the artist 's own body , face , and presence as a medium , and the latter uses materials such as clay , metal or paint which can be molded or transformed to create some physical art object .
Simplified: Performance art differs from the plastic arts , which use materials such as clay , metal or paint which can be moulded or transformed . A plastic art produces some physical art object .