Indian cinema in which Hindi films are made is called Bollywood. Only Hindi movies are made in Bollywood.
Bollywood is made up of two words, first bom and second hollywood = bollywood
Bombay means Mumbai or Bombay because the heartland of Hindi cinema is Mumbai and another word is Hollywood.
Now let’s talk about what is Hollywood?
Hollywood is the name of the film industry of the United States of America, which started in 1903. It is named after a district of Los Angeles (Hollywood) in California, in which only English language films are made.
And only after that the names of the rest of the film industry started being named from Hollywood like Bollywood, Tollywood, Lollywood etc.