Metadata: The main purpose of metadata is to facilitate in the discovery of relevant information, more often classified as resource discovery. Metadata also helps organize electronic resources, provide digital identification, and helps support archiving and preservation of the resource. Metadata assists in resource discovery by “allowing resources to be found by relevant criteria, identifying resources, bringing similar resources together, distinguishing dissimilar resources, and giving location information.” In the simplest context of SEO; metadata, (…or as they are known in SEO terms; “meta tags” or “meta elements”…) are the means by which search engines “catalog”, and make use of the information (content) contained within your website. . Meta elements provide information about the web page, which can be used by search engines to help categorize the page correctly. Web pages often (…if not always…) include metadata in the form of meta tags. The description and keywords in meta tags are commonly used to describe the Web page’s content. Most search engines use these data sets when adding pages to their search index. Search engines are – for our purposes here – generally concerned with “keywords” and “descriptions”, but may also incorporate a wide range of other relevant material for SEO purposes.
Description: the description attribute is supported by most major search engines, and they will fall back on this tag when information about the page itself is requested. The description attribute provides a concise explanation of a Web page’s content. This allows the Web page authors to give a more meaningful description for listings than might be displayed if the search engine was unable to automatically create its own description based on the page content. The description is often, but not always, displayed on search engine results pages, (SERPs) so it can affect click-through rates. The technical limitations are currently up to 155 characters per page / post / item entry.
Keywords: The keywords attribute was popularized by search engines, and it quickly grew until it became one of the most commonly used SEO elements. No consensus exists whether or not the keywords attribute has any effect on ranking at any of the major search engines today. It is currently speculated that it does; if the keywords used in the meta can also be found in the page copy itself. Therefore the relevancy of the words chosen is still important – and the technical limitations are currently up to 14 words or 155 characters per page / post / item entry.