For any website, there are things which must be included in every website. Every website needs to have these tags and not just for Google SEO
The latest Html is Html 5. Html 5 is more advanced and nowadays most browsers support HTML 5.
The older versions of Html do not support some Html tags or elements
This might cause some problems on your website to users
SEO wants the visitors to have the best user experience and if you follow the oldest Html versions, then visitors are likely to have bad experience on your website
To make sure you follow the HTML 5 version you need to declare the Doctype tag
<!DOCTYPE> <html> . . .
This is a necessary Tag for Html 5 Webpages!
This tells the Google SEO crawlers that your webpage follows the latest version of Html and this could help Google crawlers to index your website
These are other tags which are required for every website! These Tags are so important to SEO that if you exclude them, you could potentially damage your SEO
1. <Meta> - These are used to hold the meta data of the webpage such as keywords for SEO and more
2. <Title> - This is used to define the title of a webpage
3. <h1> - used to define the heading of a webpage
4. <link> - used to link any CSS style sheets or to implement any canonical tags for SEO
5. <img> - used to display images. Improves traffic and SEO score