Independent Film Previews

What is considered "independent film"? A budget of less than $30,000? Primarily shot on video and edited on a computer? In a format that would be readily accepted at any major film festival?Or is it less of a technical question and more of a philosophical one? A film that exists outside of the conventional Hollywood style of storytelling? Covers a subject matter that no major studio would touch?What do you consider to be the definition of independent film?