Although you do not have to go crazy with SEO and at the end of everything what's important is the content original and valuable we must not lose track of everything that helps to better position our site in the search engines, and microdata is a contribution that you should not underestimate.
The microdata are codes that allow a webmaster to create custom elements and apply attributes and meaning to them. Let's see, I still have not explained myself, let's see a case …
For any human being that is a person's name, but for machines it is not so obvious, as it is not they will know if it's a street name, a company name, they do not even know it's a name, they're just letters. It is information that you do not have Schema.org and you should provide, no doubt.
Well, with HTML5 microdata we "tell" searchers what they are those letters, what do they refer to? With this new concept of microdata, on the rise, search engines will have more information on how to index the information you provide, knowing if that type of data are addresses, products, people or what. Come on, that adds points in SEO.
Well, if you want to start working with the HTML5 microdata you can do it in the simplest way, with a fantastic WordPress plugin: Microdata for WordPress .
Once downloaded and activated what it does is add a new button in the WordPress editor that, when pressed, offers you a series of possible microdata (schemes) to choose from , then, fill in the necessary data to give "meaning" to the publication, to include the microdata related to the chosen scheme.
Once the fields are completed, when giving the " Save changes " button is added to your entry with a code in brackets, which contains the microdata.
A series of default schemas are defined, and you can not add more, but you can add or modify fields of each scheme by modifying the file
types.php from the "classes" folder of the plugin, now, do it with caution.
If you have any doubts about the use of the plugin, here is a video that shows how it is used … 
You can download the plugin at the following link:
Let HTML5 be with you!