Buckwheat is a pseudo-cereal—neither grass nor grain—and has nothing to do with wheat. We get ours from Australia.
Gluten-free, buckwheat flour has more protein, dietary fiber and B vitamins than an equal weight of oat or whole wheat flour. It is also an excellent source of potassium and essential amino acids. You can use buckwheat flour the same way you would use wheat flour, for baking and making pasta! You might have to adapt the quantities and ingredients though because buckwheat flour can be thicker to work with. Or you can also just replace a small portion of the wheat flour by buckwheat by 25 or 30%.