# Is a B-Spline always made up of Bezier curve segments?

According to what I have read, a B-Spline curve is made up of segments, with each segment controlled by 'k' control points (where k is the order of the curve). Also, a B-Spline curve can be formed by gluing Bezier curves together and constraining some of its control points.

More specifically, 'S' Bezier curves, each of order 'k', can be glued together to form a 'C^a' continuous B-Spline with order 'k' and kS-(a+1)(S-1) control points.

My question is:
Is the converse true? Is every segment of a B-Spline (defined by the parameter between two consecutive knot values) an individual Bezier curve, or can be represented as one?

You don't need no constraining. Given $$n$$ arbitrary Bezier curves there exist a (probably discontinuous) BSpline curve which coincide with the union of the Bezier curves in any given order.
Yes, if the spline degree is $$d$$, you can perform knot insertion until all distinct knots has multiplicity $$d+1$$. The control points of the resulting BSpline curve coincides with those of the individual Bezier curves.