The meaning for both is similar, it only can be differentiated by what happening next and will be doing indicates or suggests a picture of activity in the future. For example, I will do the dishes and I will be doing the dishes. I will do the dishes is a person stating what he going to do next, while the second sentence is more like narrating what he is doing next. 中文解释就是，我会做菜，我将会做菜。就好像加了一个助词。