Yes. There is a big difference! There are 8 fluid ounces in 1 cup. When it comes to dry ingredients, things are a bit different because 1 cup of a dry ingredient is not equivalent to 8 ounces, as dry ingredients vary greatly by weight and the dry measurement will be different. To be on the safe side when measuring out dry ingredients, use a kitchen scale. You can also specifically buy liquid measuring cups and dry measuring cups for this purpose. Have the right type on hand can certainly come in handy!