NGFB's primary function is to create meta tags (Open Graph, Rich Pin, Twitter Card, SEO, etc.). Aside from Pinterest and Tumblr, social buttons should only share a URL to the social website. The social website can then connect back to the shared URL's webpage, read the meta tags, and show the results in an overlay / popup window. The Pinterest and Tumblr sharing buttons are an exception - they must include additional information, such as a caption, media type (image, video), post type, etc.
NGFB creates accurate meta tags for titles, descriptions, images, videos, products, etc. according to your content and preferences. If you decide to use social sharing buttons from other plugins, make sure they only share the URL, and not the title, description, image, etc. -- otherwise they may share incorrect information about the webpage.
If don't use the NGFB social sharing features, and you're a bit of a performance geek, you can add the following constant to your wp-config.php file for a small performance improvement (approx. 0.0070 secs per page load).