Connecting your github account to Codechef

Codechef has recently introduced the feature to link your codechef account to github account.
What is the use of this feature? What are the benefits of connecting your github account?

Github showcases your project work. I hope you know the purpose of github. You can use it to login to your CodeChef account.

does the submit in codechef automatically gets reflected in git hub platform?

No. You have to manually create a repo and push it from your pc if you want to. The github account is just like signing in with google account where it provides your required identifying information to codechef, like name etc.