What does million usd mean?

Could you please clarify what 'million USD' actually means? I've seen it mentioned frequently in discussions about cryptocurrency and finance, but I'm still a bit hazy on the exact definition. Is it referring to a specific amount of money in US dollars? Or is there more to it? Could you elaborate a bit more on the significance of this term in the context of our field? I'm eager to understand its implications and how it fits into the larger picture of cryptocurrency and financial transactions.