The green line shows your planned mileage throughout your entire training plan and the blue line shows what you have completed so far and the blue dot represents today.
If the blue line is above the green live, you’re doing more training than prescribed and if the green is below the blue you’ve done less. Don’t try to make up training by adding in extra runs or distance, stick to the plan and don’t overdo it. Everyone misses some of their training and it’s okay.