Complex sentence: A design specification is a document providing functional and non-functional specifications, its concern is with function of a product whether it be a mechatronic motor, a side mirror for an automobile or a complete software product.
Split into simpler sentences: A design specification is a document providing functional and non-functional specifications. Its focusses on the function of a product whether it be a mechatronic motor, a side mirror for an automobile or a complete software product.