In both formal and informal logic, a main contention or conclusion is a thought which can be either true or false and is usually the most controversial proposition being argued for. In reasoning, a main contention is represented by the top of an argument map, with all supporting and objecting premises which bear upon it placed underneath.
In the context of argumentative text, it is the point that the author wants to convince you to believe - the culmination of all their reasoning. The main contention provides an answer to the following types of questions:
References
Main contention Wikipedia(Text) CC BY-SA