Yes, it's like saved posts. In fact, all of your posts can be saved in this way. Each in its own category (collection).
I understand that you're one of the developers here? Or the only one, perhaps? Well, thanks for your honesty. Seems that Eric has to do it himself, or hire a developer of his own. Shame there isn't a simple plugin for this.
Anyway, thanks for trying to help us out!

I understand so its liked saved posts? where you can save the posts you want? honestly i have no time to develop and this can be simply done by a hiring a developer

1. That register a menu for the post
2. Menu called save post/unsave post
3. A page where you can see all the posts you saved (like a seperate newsfeed).

Eric, your info and image are from before G+ introduced it's collections. Here's some better info - and a better image to go along:
">https://www.convinceandconvert.com/social-media/google-collections/

Hello Arsalan,

You're right, Google+ was terminated on april 2nd 2019. Apparently you didn't have an account there. One of the unique features of G+ was the option to create collections in which one could place one's posts - by category. It's a bit like the boards you find on Pinterest. If you'd like to see what I mean, here's a link to Quodari, the only site that I know of that has the same feature nowadays:
https://app.quodari.com/collections

it looks like this.
User can generate kind of bookmarks of favorites post, and other content
Sample image
https://www.komando.com/news/how-to-use-google-collections/838556/

What is archive posts? never saw on twitter/facebook etc. Google+ doesn't exists anymore