Latinum is a silver liquid that due to its scarcity and the fact it cannot be replicated is used as a form of currency in the Alpha and Beta Quadrants. For ease of transactions latinum is encased within gold.
The lowest common denomination of latinum used is a slip of latinum. The next highest is a strip of latinum, which is equivalent to a hundred slips. This is followed by a bar, which is equal to twenty strips or two thousand slips. The largest known denomination is a brick. (DS9: "Body Parts")