Does meta tags or keywords make the main difference??
Zero difference. Google doesn't use either for anything, they're interested in the readable content on the page and it's prominence.
The key is having good content that's written for users.
The larger the text (like headlines) the more weight it is given. But it's smarter than you might think. They're pretty good at working out the context of each word and if you try to game it, it'll be discounted.