In Writing Task 2, 

There are two main test types, including counter-argument essays (where you have to discuss two sides of a problem/ trend) and CES essays (where you have to discuss causes, effects of and/or solutions for a problem). The ways in which these test types are questioned can be various. 

There are areas of overlap between these two test types, for example, 

you are expected to be critical and state personal opinions in both.