Keep houses a couple of key features: Archive, Collections, and Downloads
Archive
The archive is where all your e-communications sent or received by your added users are housed.
The e-communication source/medium must be set up properly to feed into your archive.
E-Communications that come into your archive are what alerts are generated using risk values assigned to terms housed in lexicons and policy modules.
The Archive and the Review Inbox are very similarly laid out and share many of the same features.