In the spirit of better investing and in celebration of the first Worldwide Invest Better Day coming up on Sept. 25, Motley Fool analysts will be answering user- and reader-submitted questions leading up to the big event. "Ask a Fool" anything, and we'll do our best to help you invest better.

Have you ever wondered exactly what "the stock market" is? In the following video, Fool.com analyst Austin Smith explains that a stock market is an interconnected web of exchangers, buyers, and sellers. Investors trade small pieces of ownership of publicly owned companies, which range from the small and obscure all the way to giants like Apple a(NASDAQ:AAPL)

Click the big green button to join the thousands of people celebrating Worldwide Invest Better Day on Sept. 25!