Understanding Meta tags: Definition, meta tag analysis of a webpage of choice and description of each meta tag

 Meta tags provide information about the webpage in the HTML of the document. This information is called "metadata" and while it is not displayed on the page itself, it can be read by search engines and web crawlers.

Search engines such as Google use metadata from meta tags to understand additional information about the webpage. They can use this information for ranking purposes, to display snippets in search results, and sometimes they can ignore meta tags.

Example of meta tags include the <title> and <description> elements.

Meta tags represent the beginning of most SEO training, for better or for worse. I contemplated exactly how to introduce this topic because we always hear about the bad side of meta tags — namely, the keywords meta tag. One of the first things dissected in any site review is the misuse of meta tags, mainly because they're at the top of every page in the header and are therefore the first thing seen. But we don't want to get too negative; meta tags are some of the best tools in a search marketer's repertoire.

There are meta tags beyond just description and keywords, though those two are picked on the most. I've broken down the most-used (in my experience) by the good, the bad, and the indifferent. You'll notice that the list gets longer as we get to the bad ones. I didn't get to cover all of the meta tags possible to add, but there's a comprehensive meta tag resource you should check out if you're interested in everything that's out there.

It's important to note that in 2019, you meta tags still matter, but not all of them can help you. It's my experience, and I think anyone in SEO would agree, that if you want to rank high in search, your meta tags need to accompany high-quality content that focuses on user satisfaction.

My main piece of advice: stick to the core minimum. Don't add meta tags you don't need — they just take up code space. The less code you have, the better. Think of your page code as a set of step-by-step directions to get somewhere, but for a browser. Extraneous meta tags are the annoying "Go straight for 200 feet" line items in driving directions that simply tell you to stay on the same road you're already on!

• Meta content type – This tag is necessary to declare your character set for the page and should be present on every page. Leaving this out could impact how your page renders in the browser. A few options are listed below, but your web designer should know what's best for your site.

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

• Title – While the title tag doesn’t start with "meta," it is in the header and contains information that's very important to SEO. You should always have a unique title tag on every page that describes the page. Check out this post for more information on title tags.
• Meta description – The infamous meta description tag is used for one major purpose: to describe the page to searchers as they read through the SERPs. This tag doesn't influence ranking, but it's very important regardless. It's the ad copy that will determine if users click on your result. Keep it within 160 characters, and write it to catch the user's attention. Sell the page — get them to click on the result. Here's a great article on meta descriptions that goes into more detail.
• Viewport – In this mobile world, you should be specifying the viewport. If you don’t, you run the risk of having a poor mobile experience — the Google PageSpeed Insights Tool will tell you more about it. The standard tag is:

<meta name=viewport content="width=device-width, initial-scale=1">

references: https://moz.com/blog/the-ultimate-guide-to-seo-meta-tags