The following extract from QV would answer your question.
There are four different types of CALs available:
• Named CAL (an identified user on a server) - Access is based on user identity
and valid for all documents on the server, that is any number of concurrent
sessions from one user on one machine at a time is allowed.
• Document CAL (an identified user within a given document) - Just as
above, the access is based on user identity, but the CAL is valid only for one
document. If the same user connects to two documents using this licensing
method, he will hence consume two Document CALs.
• Session CAL - Each Session CAL allows one user to access one QlikView
document, that is to have one session at a time. Anonymous users are
allowed, no identification of the client user is necessary.
• Usage CAL - Each Usage CAL gives the right to initiate one session (single
document) per running 28-day period. The session may last a maximum of
one hour. Any activity after the first hour has expired will count as a new
session (albeit without visible interruption). No identification of the client
user is necessary.