The full size bed (also known as double bed) is, as queen size bed, also for a couple to sleep. But the mattress size is different.
The standard queen size measure 60x80”, the full size measures 54x75”. The full size bed is 6” narrower than queen size bed and 5” shorter than queen-size bed.
So the comforter itself for queen size is good for full or double bed. In fact many manufactures are made full or queen size at same size.
But if the comforter set comes with bed skirt (also known as dust ruffle), then you need think about it. Because the skirt for queen size is 60x80” + drop around (in many cases 12-16”) while full size is at 54x75”+ drop around (in many cases, 12-16”). Therefore apply a queen size skirt to full size bed will need some folding in the middle of skirt. Of courses, the skirt goes between mattress box and mattress so in many cases it is not a big deal.
If you are thinking about bedspread or quilts, then you usually do not worry about the skirt because in many cases bedspread or quilts come without the skirt. In this case, you need read the size carefully so that they are not too big or small.
Notes: There are many variations for the full, queen sizes. Full XL: 54x80”, Full XXL: 54x80”, Olympic queen: 66x80”.