Schema.org

Schema.org is a collaborative project created by Google, Bing, Yahoo, and Yandex to provide a collection of shared vocabularies for structured data on the internet. It was designed to make it easier for websites to tag their content in ways that search engines can understand, thus improving the richness of search results.
In simpler terms, Schema.org offers a standardized method to annotate your website's content with 'schema markup'. This markup helps search engine crawlers better comprehend what each page is about, which in turn can enhance the display of your site's information in search engine results pages (SERPs).
The benefits include:
  1. Rich Snippets: These are enhanced descriptions or additional information displayed on SERPs, such as star ratings for reviews, event dates, and more. This can increase click-through rates from the search results to your site.
  2. Improved SEO: By making it clear what your content is about, Schema.org markup can potentially improve your site's visibility in search rankings.
  3. Voice Search Optimization: With the rise of voice assistants like Siri, Alexa, and Google Assistant, structured data helps these systems understand and respond more accurately to queries.
Schema.org provides a wide range of schema types for different kinds of content including articles, events, local businesses, products, recipes, and more. You can implement this markup directly into your HTML code using JSON-LD, Microdata, or RDFa formats.
In essence, Schema.org is an initiative to create a common language that websites can use to communicate with search engines, leading to richer, more informative search results for users.
Schema.org is not a traditional standards organization like the ones you mentioned, but rather a collaborative project of several major search engines (Google, Microsoft, Yahoo!, and Yandex). Its primary goal is to create a shared vocabulary that webmasters can use to markup their content in ways recognized by major search engines, thereby enhancing the richness of the search results.
Schema.org's approach is more focused on a specific application of data markup for search engine understanding rather than broad technical or industrial standards. It's more of a collaborative project or initiative, rather than a traditional standards organization, though its influence can be substantial within the digital and SEO sectors.