There is only one type of "like" on X. Since June 2024, all likes (both historical and new) are hidden from profiles, but they aren't fully anonymous: post authors can still see who liked their content (unless the "liker" has a protected account the author doesn't follow). Bookmarks are the only truly private engagement—no one, including the author, can see who bookmarked a post, though the public count still increases. A retweet actively redistributes content to your followers; a like signals approval (the author will normally see it) and influences the algorithm without that same direct amplification. Prior to the June 2024 update, your feed also had likes from people you follow.