IndieBlocks (optionally) registers two “short-form” custom post types: note, and like.
In IndieWeb jargon, a note is a (short) titleless post. (That’s it!)
By defining notes (and likes) as a post type of their own (rather than a custom taxonomy or post format), they get their own admin menus, URL structure, and so on, separate from “regular” posts (“articles,” in IndieWeb parlance).
A like is an equally brief post, indicating appreciation for a certain post or web page.
To be interpreted as such, a like should be marked up using the appropriate microformats. Thanks to IndieBlocks’ Context and Like blocks, this is a lot easier than it may sound.
It’s perfectly fine to enable only the “note” post type (and therefore establish a “microblog” alongside your “regular” blog), and use the Like block to mark up certain notes (thereby “making” them likes)! A single site section or “feed” can contain more than one type of post.