Simplify the following text for a Grade 10 native English-speaking person.
Original: Currently , the largest professional wrestling company worldwide is the United States-based World Wrestling Entertainment ( WWE ) , which absorbed many smaller regional companies in the late twentieth century , as well as its primary competitors in early 2001 , World Championship Wrestling ( WCW ) and Extreme Championship Wrestling ( ECW ) . Other prominent professional wrestling companies are Total Nonstop Action Wrestling ( TNA ) and Ring of Honor ( ROH ) .
Simplified: The biggest company of professional wrestling is World Wrestling Entertainment , also called WWE .