Where are the Likes in my Tumblr theme?

Some Tumblr themes have an integrated Likes feed that displays posts you've recently liked. This feature will only be available on your main blog, not any of your secondary blogs. So enabling this feature on a secondary blog will do nothing.

We're often asked where readers can "like" a post – since every theme is a little different, it's not an easy question to answer. However, the controls to like or reblog a post will always be on the post's permalink page.

A permalink is a static URL given to an individual post, giving it a "permanent link" (get it?). In most themes, the permalink page is accessed via clicking the post's time/date information or simply a link labelled Permalink in the main feed or preview panel.