The Single license permits either a single user to use the software on multiple computers or multiple users to use the software on a single computer. However, it does not allow multiple users to ever use the software on multiple computers, regardless of whether such use is concurrent.
The Family License allows to install and use the software on up to 5 computers at a time as long as those computers do belong to the same household and are used by persons who occupy that same household. This license does not extend to business or commercial users.