Why to use "Enable Automated Archiving"?

Hello.
I’m interested in this option in backend of EasySocial:

Enable Automated Archiving
This option determines if automated archiving should be enabled. When enabled, EasySocial will archive stream items when the cronjob executes

If you have a very active social network, overtime the stream on your site will be filled pretty quickly. EasySocial comes with a built in automated archiving feature to help you clean up the stream.

It disabled on my site. What will be happen after enabling? Why this option? Will be site (server) work faster?
At the same time stream item will be disappear from Dashboard?

Usually if somebody react to video, it bump stream item (related stream item go to the top of dashboard).

How this "bump" will work if stream item is archived? Will it be unArchived and bumped? If no is it any way to unArchive and bump it?

Thanks.