SEO & Meta Tags

Content and backlinks, though it's only good practice (and highly recommended) that you use both Title tags and Description tags (keyword tags aren't important, as most SE's ignore it).

Meta keywords have been ignored for ranking purposes for quite some time as it was too easy to manipulate. To rank now you need quality, engaging content that provides useful information to your visitors - your content needs to focus on more than a single keyword phrase, it must cover the topic that you're discussing/offering information about. Take a look at the top 10 results for your keyword phrase - quite often you'll now find that some of them don't even have the keyword phrase in the title or description but the page covers the topic and includes related phrases, keywords, niche-specific slang etc.

Find common phrases in the top 10 results and include these in your page. Write for your audience and not for the keyword - when you read the article would it be good enough to be published in a magazine? If not, then it's not good enough for your audience either.

High quality in-content backlinks are also an important factor but don't rely on Google organic searches for all your traffic.

meta tags update is huge part of role playing in SEO

They use their main keywords in title and description. Because google doesn't gives any value to meta keywords.

Mega tags hardly play a role in SEO. But they are quite important for click through rate.

There is no more trend of using meta keywords and this will not help any more in SEO, so mentioning meta keywords is negative point for your site as it gives idea to your competitor that which keywords most specifically you are targeting