Products containing inherent defects that cause harm to a consumer of the product, or someone to whom the product was loaned, given, etc., are the subjects of products liability suits. Products liability claims can be based on negligence, strict liability, or breach of warranty of fitness depending on the jurisdiction where the claim is based. Many states have enacted comprehensive products liability statutes. There is no federal products liability law. In any jurisdiction, a common denominator of any products liability case is the need to prove that the product is defective.
Design defects are inherent, they exist before the product is manufactured.
While the item might serve its purpose well, it can be unreasonably dangerous to use due to a design flaw. On the other hand, manufacturing defects occur during the construction or production of the item. Only a few out of many products of the same type are flawed in this case. Defects in marketing deal with improper instructions and failures to warn consumers of latent dangers in the product. Products Liability is generally considered a strict liability offense.