We recommend to scan IP ranges because of a few reasons. When scanning an IP range you will automatically discover new hosts within the IP range when they come alive. For example if you deploy a new web server it will automatically get scanned.
Another advantage of scanning IP ranges is that you keep track of what host that are responding and what ports that are open. By doing that you will notice if hosts respond, that should not respond, and ports that are open, that should not be open.
Notice that our scan engine never scans a host more than once in a single scan run. As an example, if a host exists within an IP range and a tag, and both the IP range and tag is set to a target for a scan run, the host will only be scanned once.