Hi deepankerchawla - When you have the "Widgetized community home page" enabled, this means that your landing page in Jive will have an "Overview" page layout that is comprised of customizable widgets. These widgets can be the Recent Blog Posts widget, Slideshow Carousel, Recent Activity, Featured Content, etc. When this is enabled you will see a new list on the left navigation called "Overview":
The widgetized homepage is a great way to provide a customized landing page for your community. You can see the homepage in Jive Community by going to https://community.jivesoftware.com/welcome
If you have the widgetized homepage disabled, then this "Overview" page link will not be shown to users, and your top link will be the "Activity" page:
Let me know if this helps answer your question.