A schema is a piece of code designed for search engines to see a full picture of a website’s content. Schema allows search engines to gather extra data you would not normally display on your website. Search engines use schema to better understand and rank web pages. This is why schema is a potent and valuable SEO tool.
There is so much you can communicate to search engines through schema. For instance, you can inform Google of the price range you offer without directly saying it. Without schema, Google can never know your products’ brand information, nor can it understand that you sell items in different colors or different sizes, for example.
You want Google to know more about your website so that it has a higher chance of being picked for organic searches.
We see schema as reading a book's synopsis on its back cover. It helps us get familiar with the book’s plot and its idea before deciding whether to buy it or not.