Understand distinction between Spearman’s rank correlation coefficient and PMCC

Understand the distinction between Spearman’s rank correlation coefficient and Pearson’s product moment correlation coefficient (PMCC).

e.g. recognise the relative strengths of rank correlation and product moment correlation on a scatter graph.
The PMCC measures the strength of linear correlation.
The calculation of PMCC will not be required.
e.g. if there is positive non-linear correlation both coefficients will be positive but Spearman’s coefficient will be greater than PMCC.