Importance of Meta title – Title is the most important factor for web pages to understand search engines about your website page. Write effective relevant title between 49 to 55 characters. Google recommended up-to 69 to 75 characters depends on pixels (current strategy is 600px).
Importance of description – Description means summary of your page. Explain about your page information between 150 to 155 characters. Google says description is not ranking factor, but we observed Meta description is one of the best technology for SEO rankings.
Importance of keywords – Meta keywords are not important. If you want update keywords you can update in the title and content.
Plug-in for SEO Meta Tags
Meta data for Social Media Pages – Write Meta tags for your social media pages and profiles (facebook, Google plus twitter) to using yoast plugin. Search engines will pick up your social media data to display in search engines.
Write SEO Meta tags in the informative way, avoid business and keyword target promotion titles, you can concentrate only on subject of your webpage and information.