A datasheet, data sheet, or spec sheet is a document that summarizes the performance and other characteristics of a product, machine, component (e.g., an electronic component), material, subsystem (e.g., a power supply), or software in sufficient detail that allows a buyer to understand what the product is and a design engineer to understand the role of the component in the overall system.

A data sheet describes the technical characteristics of an item or product, often published by a manufacturer to help people choose or use the products. A data sheet is not a technical specification in the sense of informing how to produce.

A spec sheet, also known as a specification sheet, is a business one pager document that provides a list of a product’s features and characteristics. It articulates the product's features, specifications, and details—the what, how, and why behind the production and sales.

A technical specification is a detailed and comprehensive document that describes all technical procedures related to product development. It covers all the vital, nitty-gritty information about the process of product development.

A garment specification (spec) sheet, or measurement table, is a technical document that contains all construction details of the garment. It looks like a technical diagram or a sketch of a garment, including all of its measurements. Spec sheets are used by designers to communicate design concepts to manufacturers.