Cotton, and why the staple matters
Face, back and filling are all cotton. A polyester filling is cheaper and warmer for its weight, but it does not breathe, and a quilt that does not breathe is a quilt you push off at two in the morning.
The fabric
Quilted cotton
Two layers and a filling, held together by the stitching that gives it its face.
The stitching is the design
The quilting line does two jobs: it stops the filling shifting, and it draws the cloth in so the surface gathers between the lines. That gathering is where the texture comes from.
Wash it whole, dry it slowly
Use a large machine so the quilt can move, and dry on low with plenty of room. A cramped dryer is what makes the filling bunch.
Questions about this fabric
Is a quilt warm enough on its own?
For summer and for a mild room, yes. In winter it works as a layer over a duvet.
Will the filling move?
Not if the quilting lines are close enough, which is what you are paying for. Dry it with space and it stays even.
Can it go on the bed all year?
That is what it is for. Spread in summer, folded across the foot the rest of the year.