Thank you for your reply. And thats right that it is not an issues but this question is come in development only. because I described that even I remove that widget line then there is no effect in theme. So that remove or adding some code is done by developer only. so as per the description this question is ask in development only.No, You don't have knowledge about widget it will not comes under development issue.
You can learn from nopCommerce document. What is widget and how it can be used. Widget is something to display custom things in page without customization. e.g Nivo slider in nopCommerce coming from widget.
Look below code:
Now here is common things. Look what is mean of other lines. TaxType, Currency & Language Selectors and you can add yours custom things after those selector(dropdown) in header using header_selectors widget. So you don't need to customize in this page.
Let me know if you have any question or query.