Difference between Correlation and Regression

Correlation

It measures mutual relationship between two or more variables.
Does not involve cause and effect relationship.
Confined to the study of linear relationship.
Sometimes correlations may be non-sense with no practical relevance.
It measures degree and direction of mutual relationship between 2 or more variables.
It is independent of the unit of measurement.

Regression

It measures functional relationship between two variables
It indicates cause and effect relationship.
It studies both linear and non-linear relationship.
There is no such thing like non-sense regression
It measures degree of dependence of one variable on the other(s).
It is in the unit of the measurement of variable.