What is the difference between Going to and Will?

Going to and will are words that are used that will signify that something will be done in the future. These two words are used in the simple future tense. When you say will, this means that you would like to do something immediately. When you say going to, this means that you are going to do something eventually.
It is possible that when you use going to, this already means that you are going to do something in the future that you have already planned beforehand. You can use the right words, depending on which one you feel will be more appropriate for the things that you want to say.