A configuration is a particular pose of the kinematic_structure. It can be precisely defined by the orientation of all joints in a structure.

EXPRESS is a data type definition language developed for and used by the STEP community.

Kinematics: "the description of movable mechanical structures consisting of joints and links including the number, location, and orientation of the joints."

The STEP standard is very big and is published as a series of documents called Parts. The Kinematics document is formally called "ISO 10303 Part 105: Integrated Application Resource: Kinematics."

The revolute pair constrains the motion between two adjacent links to a rotation about a common axis. To measure the angle of rotation a frame is defined on each of the links such that local origins and the z-axes coincide and their positive directions agree.

A schema is a collection of semantically meaningful data types which defines a domain e.g. kinematics. Schemas in STEP are defined in the EXPRESS Language.

STEP the Standard for the Exchange of Product Model Data is an International standard (ISO 10303). Step provides a representation of product information enabling product data exchange.