What is Coherence in IELTS Writing Task 2 ? - understanding coherence "Visually"

There are many frequently discussed terms roam in the  mind when we start exploring IELTS . Some terms are little bit tricky to be understood clearly .Coherence and cohesion is one of the four elements assessed  in your IELTS writing task 2 (General and Academic) and widely spoken about, in various IELTS mentoring sites . Let me take "coherence" for this post today.

Coherence

If you want to know in a nut shell ,I would say coherence is "Central point of the paragraph " . You build a paragraph on one main idea and maintain it properly with carefully developed phrases ,words and examples .

For instance , let's see the following task on a "Coherence Map" which is  invented and illustrated by Knowledge Universe for the first time(2016)