AOC stands for Area of Concentration. This is a specific type of training designed to target a specific area that you may be having difficulty making gains in. We can have what I like to term stubborn areas, parts of our bodies that seem resistant to making improvements. For example, personally speaking my calves are underdeveloped. This is a specific area that I am currently calling my Area of Concentration.
Through the knowledge that I have acquired I have the "tools" to help myself and you meet the desired goals in our Area of Concentration!