'print render($content['links']);' Which links is Drupal referring to in 'print render($content['links']? 'Links' is kind of general to me so I am wondering which links this php snippet is referring to.

I've looked at Drupal's theming references and saw only a list of variables for theming.
The links it is referring to are the comment links, statistics links and translation links of a node. 

So in a situation where you want just the comment links, it would be 

print render($content['links']['comment']);


For more information, see this page.

https://api.drupal.org/api/drupal/includes%21common.inc/function/drupal_pre_render_links/7