Other forms: future tenses
In grammar, the future tense is the verb form you use to talk about things that haven't happened yet. When you say, "The party will be so fun!" "will be" is in the future tense.
Whenever you write or talk about things that you expect to happen later, you use the future tense. If your grandmother says, "We will bake cookies tomorrow," she is using the future tense to make it clear that nobody's baking cookies today — you'll have to wait until tomorrow. The future tense can be more complicated than this simple form, but it always signifies an intended or expected future action.