These crawls are part of an effort to archive pages as they are created and archive the pages that they refer to. That way, as the pages that are referenced are changed or taken from the web, a link to the version that was live when the page was written will be preserved.
Then the Internet Archive hopes that references to these archived pages will be put in place of a link that would be otherwise be broken, or a companion link to allow people to see what was originally intended by a page's authors.
Likes are represented by a small heart. They are commonly used to show appreciation for a Tweet. You can see someone’s likes by visiting their profile, and your likes are also visible on your profile.
To like a Tweet:
Make sure you are logged in to Twitter.
Click or tap the heart and it will turn red, confirming that you've liked the Tweet.
You can also like a Tweet from a user's profile page and a Tweet's permalink page.
Note: If you like Tweets by users who have protected their Tweets, the update will not appear in the Likes tab on your profile (unless the viewer is a follower of the Tweet's author).
To undo or remove a like:
Log in to Twitter.
Find the Tweet you liked (the heart will be red).
Click or tap the heart to undo the like.
How do I see what other people have liked?
See what other people have liked by going to their profile:
On the web, go to the profile page of the account and click on the Likes tab at the top of the Tweet timeline.
In the Twitter app(iOS or Android), go to the profile of the account and tap Likes.