A parity plot is a scatterplot that compares experimental data against tabulated data. Each point has coordinates (x, y), where x is the tabulated value, and y is the corresponding experimental value.
A line of the equation y = x is sometimes added as a reference. When an experimental value equals a tabulated value, the point will lie on the line.
Parity plots are found in scientific papers and reports, when the author wishes to compare his data to accepted values in an easily understandable way.
References
Parity plot Wikipedia(Text) CC BY-SA