Specifications are documents that define technical requirements, which products, materials or services must meet.
For a product manufacturer, specifications are a certificate according to which all products are produced: from creation of dummies to delivery of finished products to the customer. The manufacturer has duties to the client to provide a required level of production quality, which should not be below the specifications.
For product consumers, specifications are a document based on which you can verify compliance with the requirements of the product quality, and based on test results reach a conclusion as to whether the supplier fulfilled its direct obligations concerning the product quality.
Specifications are developed based on one or several specific products. The requirements stipulated by the specifications should not contradict the mandatory requirements of the state (interstate) standards covering the product.