The Comments plugin lets people comment on content on your site using their Sharesome account. If people wish to they can share this activity to their friends in News Feed as well. It also contains built-in moderation tools and special social relevance ranking.
Place the code wherever you want the button to appear on your page
Include the JavaScript SDK on your page once, ideally right after the opening <body> tag
This script works for all the plugins, so you don't need to include it again for Like plugin.