Schema webpage tags
To me schema is the future of communicating content on the web. In the modern day search engines can easily effectively crawl and pick out keywords. But schema tags add a much more structured way of organising and communicating your pages to search engines. To a search engines a web page is usually just a web page, but with schema you can do things like say, this is a web page, here is the breadcrumb, here are the separate articles and sections on the page. At the minute schema is quite complex and contains a lot of different tags to explain different things. Schema is pretty much a necessity for every site on the web, it really is the standard now and you should be using it on your site. Both Google and Bing / Yahoo support Schema tags.
Nesting Schema tags
You should get into the habit of attaching a top level Schema to your HTML tag or your body tag. This top level Schema tag can act as wrapper for all your nested schema below. For example on a product page you may have a breadcrumb and a product Schema nested below your top level Schema. On an information page you may have a breadcrumb and an article Schema nested. If you are dynamically generating your pages using PHP or similar you may have a header template file and you can attach this top level Schema to it and it will run across all your template pages. There is a varied selection of Schema tags now available to cater for any need really and if you put in the time you can break up your page into a very clear structure for search engines and improve your ranking and click through rate. You may want to look at either planning your Schema out on paper for your pages or using a HTML editor and build your Schema structure before you build your pages. Nesting tags can become quite tricky or you are nesting very deep and you page contains a lot of HTML. You can use the Google Structured Data Testing tool to make sure your Schema shows properly but you must also look at manually checking your Schema in the SERP to ensure your search result is showing Schema in the right way. If you have something like a product Schema and you do not ever see things like price or availability ever showing it could mean a nesting error even if everything looks fine in the Google Structured Data Testing tool.
<body itemscope itemtype="http://schema.org/WebPage"> // Webpage Schema attached to a body tag
// Nest other Schema within
Schema in the search results page
Perhaps the biggest benefit of Schema tags is the fact you can use them to enhance your page in the SERP. When your page shows in results for a search query it is the portal into your site, and its bundled within a lot of other search results. You want and need it to stand out, you can do this partially with your Meta title and Meta description of course, but with Schema you can also do things like display the price of a product you are selling. This is instantly something that will grab a buyers attention and if other sites have their Schema tags showing and your price is lower, all the better for you. Even better than that is if you are the only one that has the price showing, you’re much more likely to get a click than someone who doesn’t. There aren’t a whole lot of things you can do in regards to Schema helping your display in search results, but the small number of things that you can do matter a lot.
For a full list of supported Schema visit schema.org