@schuetzler@shanselman@borland@tf bookmarks are not public and the author of the original toot doesn't get a notification. A like "says something" while a bookmark is a bookmark.
@schuetzler@shanselman@borland@tf bookmarks are for yourself to remember a toot for later. Favs can also do that, but they also show the author appreciation.
@valder@shanselman I think what Boost does is it bumps it back up to the top of all the feeds. (Home feed for your followers, local feed for everyone else on your instance.)