Difference between Retesting and Regression testing?

Retesting	Regression
Retest is carried out when a particular defect is fixed and tester has to run through the test cases related only to the defect fixed	Regression testing is carried out to check if the defect which is fixed in the module has affected any other module or not. Here tester has to run through the whole module i.e. the test cases which are already passed too and not a particular test case.
Retest is carried out to check if the prior defect which is logged has been rectified.	Regression testing in laymen term is to check if there are any side effect to the defect fixed.
Retest is a planned testing	Regression testing is generic testing