That js looks to be the JQuery library, not any of Google's libraries. You may have gotten it confused with Google because many sites will embed the JQuery source via any one of the various CDN's, one of which belongs to google. For example, you may have seen this:
https://ajax.googlea...3/jquery.min.js
Notice "jquery" on the end? The above link is to the JQuery library hosted on the Google CDN. That is not to say that the code belongs to google at all, only that it is hosted on a google server.
JQuery normalizes javascript across different browsers allowing developers to create client-side apps without worrying about browser compatibility. DOM manipulation, visual effects (fades, sliding, etc) and AJAX are some of the things that JQuery does.
Google Maps is not part of JQuery.
You can review all of Goolge's apis here:
https://developers.google.com/
The term "placeholder" that you've used many times has no relevance to the topic... I just assumed that you are talking about script tags.