STEP is an interface standard (ISO 10303), initiated from ISO, exceeding the pure geometry data exchange (like DXF or IGES). With STEP possibly all product data, assaulting during the product durability, should be displayed and transmitted between different CAx systems. All information  of a product are included - beginning from layout up to its close-down. Data is assaulting in construction, calculation, production, assembly, quality control, maintenance and operation. The product model concept of STEP depends on the generation of a complete model, dividing in Parital models with certain, limited information contents, being linked and related with each other. STEP contains several standards, being defined via a special language with each other and consists of so called Parts, Application Protocols and Conformance Classes.

It is possible to integrate in the geometry description all forms (wire frame, surface and volume models) from CAD data models. The application protocol AP 203 Class 2 describes wire frame and surface models, Class 4 defined surface models with topology and Class 6 is responsible for volume models. AP 214 is especially used for the automotive industry and can e.g. transmit structure information (colors, levels, groups). With STEP it is possible to forward information at assemblies via the hierarchic structure.

The society ProSTEP was founded to facilitate the realization of standard STEP into standard products and services.