What Are Twitter Cards?
Twitter Cards allow you to attach link previews with photos and link titles to your tweets. Twitter cards look like this when published to Twitter:
Your followers can click on the Twitter Card to be taken to the link.
Types of Twitter Cards
There are several types of Twitter Cards:
To learn more about adding Twitter Card meta tags to your website, please see Twitter's Getting Started Guide.
Add Twitter Cards to a WordPress blog
First, install the WordPress SEO by Yoast plugin.
Open the Yoast plugin.
Click on the Social settings under the menu.
Click on the Twitter tab.
Check the Add Twitter Card Meta Data option and input your Twitter username.
Select The default card type you want to use and save.
Twitter Card Validator
Double check that your Twitter cards are working with the Twitter Card Validator.
If you run into errors when validating your links, check out Twitter’s Troubleshooting Guide.