What does it mean: the amount of hydrogen substance is greater than the amount of oxygen?

What does it mean: the amount of hydrogen substance is greater than the amount of oxygen? Does this mean that the mass of hydrogen is greater than the mass of oxygen?

This means that there are more structural units of hydrogen (molecules for example) than, for example, oxygen molecules (structural units of oxygen).
But this does not mean that the mass of hydrogen is greater than the mass of oxygen, because a hydrogen molecule is much lighter than an oxygen molecule.

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