Simplify the following text for a Grade 17 native English-speaking person.
Original: A Chief Executive Officer ( CEO ) , or Chief Executive , is the highest-ranking corporate officer , administrator , corporate administrator , executive , or executive officer , in charge of total management of a corporation , company , organization or agency .
Simplified: A chief executive officer ( CEO , American English ) , managing director ( MD , British English ) , or chief executive is the highest-ranking corporate officer ( executive ) or administrator in charge of total management of an organization .