A strong, positive correlation between ice cream sales and shark attacks does not imply that eating ice cream causes shark attacks. Why?

Correlation is study of mutual relationship between two variables, without any variable being 'dependent' or independent'.

Explanation:

Correlation is statistical measure of mutual relationship between two variables, denoting how they fluctuate together. Eg : Correlation between nutritious status & severity of illness of a patient.

However, Correlation study doesn't define variables as : Independent (Causal) Variable, which effects the Dependent Variable.

The above study is 'Regression' which defines dependent variable (s) effected relationship from independent variable (s). Eg : Law of demand - price demand inverse relationship - price is the independent variable affecting dependent variable demand

So, Positive Correlation between Ice Cream Sales & shark attacks just implies that they move in same direction - one increase, other increase & one decrease, other decrease. It specifies nothing about change in which (independent) variable brings change in which (dependent) variable. As stated - Ice creams being independent variable affecting shark attacks, is not Correlation concept.