Representation
Also called Physical representation
College Board defines a representation as a method of understanding and communicating understandings about physics. A representation is a depiction of a model, or of some aspect of that model, such as a graph, a diagram, an equation or a written description.
The definition above is quoted from the appendix Vocabulary and Definitions of Important Ideas in AP Physics, which appears at the back of all four course descriptions. It follows on from models: once a scientist has fixed the boundaries of a model, a representation is how those boundaries get communicated to somebody else.
The list is course specific. AP Physics 1 names eleven kinds that it says are frequently used, though not limited to: written descriptions, drawings and pictures, diagrams or schematics, mathematical equations or sets of equations, graphs and data tables, charts, motion maps, energy bar charts, momentum charts, free-body diagrams and force diagrams. AP Physics 2 drops motion maps and momentum charts from its list and adds ray diagrams, vector maps, field lines or field line maps, and equipotential lines. AP Physics C: Mechanics and AP Physics C: E and M each print their own version.
Creating them is a graded skill, not a study aid. Science Practice 1 is Creating Representations, and skill 1.A asks you to create diagrams, tables, charts or schematics to represent physical situations. The appendix states that the exam will use many representations and will require students to create many.
Translation between them is the other half. All eight AP Physics 1 unit progress checks list Translation Between Representations as one of their four free-response task categories, and the CED's suggested strategy called Changing Representations asks students to go from, say, a motion map to a free-body diagram.