The Difference Between Future Simple and Future Perfect

Think about what you're doing at the moment and project it into the future. If we say I will have done my homework by 6pm, this time we are saying in this case we're moving the reference point to sometime in the future after 6pm. Did that make it better or did that make it worse? I'm not sure. Maybe this isn't something you need to understand right now in your studies. But if it's really a struggle for you, as I said it's not the end of the world, just sometimes.