Javascript initialization (Metronic)

Hello to all.
I am a new member of this forum. I just started to use Metronic Admin Template, can someone explain to me what these following lines of code do?
Can I omit them?

Thank you for replying to me.

Hi frank86, welcome to ThemeForest, this is a general open forum.



For specific pre-sales questions, you can interact directly with the author here. If you’ve already purchased the template and need assistance, don’t forget to post from the buyer account instead. Thanks.