Idiom of the day.
No big deal.
No big deal means, it's not a big problem, it's not anything to worry about.
For example, if you've made a mistake at work and you tell your colleague, your colleague
might say, "Don't worry, it's no big deal."
That means there's nothing to worry about.
So, if you'd like to use this expression in your everyday language but you've forgotten,
don't worry, it's no big deal, simply watch the video again.