We been doing SEO since 2009 and at that time, meta tags is one of the key component to SEO.
For example: If a website is about weight lose, on every page, it is recommended to put meta tags such as “weight lose, losing weight, diet, weight loss tips, how to lose weight, etc etc”.
In 2011/2012, Google change their algorithm again, they no longer focus on meta tags or meta keywords.
This is due to many “SEO guru” stuffing the keywords in their meta tags include us! Haha.
Today, Google focus on meta description where in every page/post, you are should type a short summary of what this page is about.
See below for example.
Take note that meta description has a different content from the website.
It is mainly a summary of what this page is about.
Video of Matt Cutts talking about meta tags vs meta description.