Google has a several ways to index and examine your site and among them Meta tags usage is also one. Meta tags are generally used to describe the theme and introduction of your website and it needs to be very powerful too. Generally Meta tags visible when somebody search on a specific website and get that and it appears as a short description of that site. Usage of correct Meta Tags attract more visitors to your site and can increase your page rank on the search engines and help the search engines like Google in classifying your website. As a broad rule about a clear and brief Meta Tag always help to improve your page ranking on Google and other search engines. But, Google completely ignores the Keyword Meta Tags listed because of harms with spam in what went before. They may use Meta Descriptions in their search results.

Basically usage of Meta tags in SEO was started by Google itself in the year 1998 and somehow indexing through algorithms had a slowdown on some areas and it was proved a turning point in terms of increasing search engine result pages or SERPs. The changes was started to notice like the web pages who had the keywords as same the meta tags and was also used in the content of the pages was definitely had a higher traffic on their site and indeed had a higher page rank too. Google has never used Keywords Meta Tags to count their search engine results pages but look for the keywords usage in your web page content and through that and you get your page rank increases by that.