A more thorough explanation:

A performance specification is a part of a contract that outlines what one party, usually the seller, will do for the other party, usually the buyer. It is often included in a statement of work, which covers terms such as inspection, quality assurance, packing, data requirements, and training.

There are two types of specifications in a statement of work:

• Performance specification: This establishes the minimum requirements for the items to be supplied.
• Design specification: This establishes the methods to be used in meeting those minimum requirements.

For example, if a company is buying a new computer system, the performance specification might include requirements for processing speed, memory, and storage capacity. The design specification might outline the specific components and software that will be used to meet those requirements.

Overall, a performance specification helps ensure that both parties understand what is expected and that the seller delivers a product that meets the buyer's needs.