Context is the table in the relationships graph from which a
relationship is evaluated. When you define a calculation in a source table, and the table has more than one occurrence in the relationships graph, you must specify the context from which you want the calculation to evaluate.
Because the relationships use different match fields, each relationship returns a different set of related records.
A calculation field defined in the ColorsSourceTable with the formula Sum(ShapesTable::Price) that is set to evaluate from the context of the table ColorsTable 1 returns the value $8.00.
A second calculation field defined in the ColorsSourceTable with the same formula, Sum(ShapesTable::Price), but set to evaluate from the context of the table ColorsTable 2 returns the value $15.00.