This video explains about jquery inner width function.
using inner width function we can get and set the inner width property of given elements.
please inner width means = element width + padding - left + padding - right.
I need you to try these cases on your machine and also do try few crazy scenarios if you can.
If you get stuck or if you have any query then please do comment below and let me know.
I will try to reply you as soon as possible.