In the context of your life plan, your values are the way you will describe the order of priority between competing aspects of life.
Value is a measure of preference among a set of things. Just as a dictionary must define a word by using other words, the degree to which you value something can only be defined in terms of the value of other things. Until and unless you explicitly define the ranking of your preferences, it is extremely unlikely that you consistently act toward what will bring you the greatest joy.