What exactly is “The Dow?” “Nasdaq?” (in super-layman’s terms, please)?

Harriet: What exactly is “The Dow?” “Nasdaq?” (in super-layman’s terms, please)?
I don’t know anything about the stock market or Wall Street.

What exactly is “The Dow?” “The Nasdaq?”

Thanks!

Answers and Views:

Answer by tro
these are stock exchanges and there are certain types of companies that subscribe to their exchange(there is a third one as well)
you will notice they have very divergent figures regarding transactions because companies don’t belong to each of them and therefore are not traded thru their exchange