Residual time is the amount of time left over after you finish doing something. It's just like when you have some juice left in your cup after you drink it all up. The juice that's left in the cup is the residual juice, and the time that's left after you finish something is the residual time.
Let's say you have an appointment with the doctor that lasts for 30 minutes. After the appointment is over, if you have some time left before you need to go somewhere else, that's your residual time. It's like the extra time you have left in your day to do whatever you want to do.
Residual time is important because it can help you manage your time better. If you plan your day carefully, you can make sure that you have some residual time left over to relax or do something fun. It's like a reward for finishing your tasks on time.
So, always make sure you have enough residual time in your day to do what you want, and make the most out of it!